Release 1.47.0
diff --git a/INSTALL b/INSTALL
new file mode 100644
index 0000000..0f669e6
--- /dev/null
+++ b/INSTALL
@@ -0,0 +1,8 @@
+See ./index.html for information about this release. The "Getting Started" 
+section is a useful starting place.
+
+---------------------------
+Copyright Beman Dawes, 2008
+
+Distributed under the Boost Software License, Version 1.0.
+See ./LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt 
\ No newline at end of file
diff --git a/Jamroot b/Jamroot
new file mode 100644
index 0000000..c5557b8
--- /dev/null
+++ b/Jamroot
@@ -0,0 +1,263 @@
+# Copyright Vladimir Prus 2002-2006.
+# Copyright Dave Abrahams 2005-2006.
+# Copyright Rene Rivera 2005-2007.
+# Copyright Douglas Gregor 2005.
+#
+# Distributed under the Boost Software License, Version 1.0.
+#    (See accompanying file LICENSE_1_0.txt or copy at
+#          http://www.boost.org/LICENSE_1_0.txt)
+
+# Usage:
+#
+#   bjam [options] [properties] [install|stage]
+#
+#   Builds and installs Boost.
+#
+# Targets and Related Options:
+#
+#   install                 Install headers and compiled library files to the
+#   =======                 configured locations (below).
+#
+#   --prefix=<PREFIX>       Install architecture independent files here.
+#                           Default; C:\Boost on Win32
+#                           Default; /usr/local on Unix. Linux, etc.
+#
+#   --exec-prefix=<EPREFIX> Install architecture dependent files here.
+#                           Default; <PREFIX>
+#
+#   --libdir=<DIR>          Install library files here.
+#                           Default; <EPREFIX>/lib
+#
+#   --includedir=<HDRDIR>   Install header files here.
+#                           Default; <PREFIX>/include
+#
+#   stage                   Build and install only compiled library files
+#   =====                   to the stage directory.
+#
+#   --stagedir=<STAGEDIR>   Install library files here
+#                           Default; ./stage
+#
+# Other Options:
+#
+#   --build-type=<type>     Build the specified pre-defined set of variations
+#                           of the libraries. Note, that which variants get
+#                           built depends on what each library supports.
+#
+#                               minimal (default) - Builds a minimal set of 
+#                               variants. On Windows, these are static 
+#                               multithreaded libraries in debug and release
+#                               modes, using shared runtime. On Linux, these
+#                               are static and shared multithreaded libraries
+#                               in release mode.
+#
+#                               complete - Build all possible variations.
+#
+#   --build-dir=DIR         Build in this location instead of building
+#                           within the distribution tree. Recommended!
+#
+#   --show-libraries        Displays the list of Boost libraries that require
+#                           build and installation steps, then exit.
+#
+#   --layout=<layout>       Determines whether to choose library names
+#                           and header locations such that multiple
+#                           versions of Boost or multiple compilers can
+#                           be used on the same system.
+#
+#                               versioned - Names of boost binaries
+#                               include the Boost version number, name and
+#                               version of the compiler and encoded build
+#                               properties.  Boost headers are installed in a
+#                               subdirectory of <HDRDIR> whose name contains
+#                               the Boost version number.
+#
+#                               tagged -- Names of boost binaries include the
+#                               encoded build properties such as variant and
+#                               threading, but do not including compiler name
+#                               and version, or Boost version. This option is
+#                               useful if you build several variants of Boost,
+#                               using the same compiler.
+#
+#                               system - Binaries names do not include the
+#                               Boost version number or the name and version
+#                               number of the compiler.  Boost headers are
+#                               installed directly into <HDRDIR>.  This option
+#                               is intended for system integrators who are
+#                               building distribution packages.
+#
+#                           The default value is 'versioned' on Windows, and
+#                           'system' on Unix.
+#
+#   --buildid=ID            Adds the specified ID to the name of built
+#                           libraries.  The default is to not add anything.
+#
+#   --python-buildid=ID     Adds the specified ID to the name of built
+#                           libraries that depend on Python.  The default 
+#                           is to not add anything. This ID is added in 
+#                           addition to --buildid.
+#
+#
+#   --help                  This message.
+#
+#   --with-<library>        Build and install the specified <library>
+#                           If this option is used, only libraries
+#                           specified using this option will be built.
+#
+#   --without-<library>     Do not build, stage, or install the specified
+#                           <library>. By default, all libraries are built.
+#
+# Properties:
+#
+#   toolset=toolset         Indicates the toolset to build with.
+#
+#   variant=debug|release   Select the build variant
+#
+#   link=static|shared      Whether to build static or shared libraries
+#
+#   threading=single|multi  Whether to build single or multithreaded binaries
+# 
+#   runtime-link=static|shared      
+#                           Whether to link to static or shared C and C++ runtime.
+#   
+
+# TODO:
+#  - handle boost version
+#  - handle python options such as pydebug
+
+import boostcpp ;
+import package ;
+
+import sequence ;
+import xsltproc ;
+import set ;
+import path ;
+
+path-constant BOOST_ROOT : . ;
+constant BOOST_VERSION : 1.47.0 ;
+constant BOOST_JAMROOT_MODULE : $(__name__) ;
+
+boostcpp.set-version $(BOOST_VERSION) ;
+
+project boost
+    : requirements <include>.
+      # Disable auto-linking for all targets here, primarily because it caused
+      # troubles with V2.
+      <define>BOOST_ALL_NO_LIB=1
+      # Used to encode variant in target name. See the 'tag' rule below.
+      <tag>@$(__name__).tag
+      <conditional>@handle-static-runtime
+      # The standard library Sun compilers use by default has no chance
+      # of working with Boost. Override it.
+      <toolset>sun:<stdlib>sun-stlport
+      # Comeau does not support shared lib
+      <toolset>como:<link>static
+      <toolset>como-linux:<define>_GNU_SOURCE=1
+      # When building docs within Boost, we want the standard Boost style
+      <xsl:param>boost.defaults=Boost
+    : usage-requirements <include>.
+    : build-dir bin.v2
+    ;
+
+# This rule is called by Boost.Build to determine the name of target. We use it
+# to encode the build variant, compiler name and boost version in the target
+# name.
+#
+rule tag ( name : type ? : property-set )
+{
+    return [ boostcpp.tag $(name) : $(type) : $(property-set) ] ;
+}
+   
+rule handle-static-runtime ( properties * )
+{
+    # Using static runtime with shared libraries is impossible on Linux,
+    # and dangerous on Windows. Therefore, we disallow it. This might
+    # be drastic, but it was disabled for a while with nobody complaining.
+
+    # For CW, static runtime is needed so that std::locale works.
+    if <link>shared in $(properties) && <runtime-link>static in $(properties) &&
+        ! ( <toolset>cw in $(properties) )
+    {
+        ECHO "error: link=shared together with runtime-link=static is not allowed" ;
+        ECHO "error: such property combination is either impossible " ;
+        ECHO "error: or too dangerious to be of any use" ;
+        EXIT ;
+    }
+}
+
+all-libraries = [ MATCH .*libs/(.*)/build/.* : [ glob libs/*/build/Jamfile.v2 ]
+    [ glob libs/*/build/Jamfile ] ]
+    ;
+
+all-libraries = [ sequence.unique $(all-libraries) ] ;
+# The function_types library has a Jamfile, but it's used for maintenance
+# purposes, there's no library to build and install.
+all-libraries = [ set.difference $(all-libraries) : function_types ] ;
+
+# Setup convenient aliases for all libraries.
+
+local rule explicit-alias ( id : targets + )
+{
+    alias $(id) : $(targets) ;
+    explicit $(id) ;
+}
+
+# First, the complicated libraries: where the target name in Jamfile is
+# different from its directory name.
+explicit-alias prg_exec_monitor : libs/test/build//boost_prg_exec_monitor ;
+explicit-alias test_exec_monitor : libs/test/build//boost_test_exec_monitor ;
+explicit-alias unit_test_framework : libs/test/build//boost_unit_test_framework ;
+explicit-alias bgl-vis : libs/graps/build//bgl-vis ;
+explicit-alias serialization : libs/serialization/build//boost_serialization ;
+explicit-alias wserialization : libs/serialization/build//boost_wserialization ;
+for local l in $(all-libraries)
+{
+    if ! $(l) in test graph serialization
+    {
+        explicit-alias $(l) : libs/$(l)/build//boost_$(l) ;
+    }
+}
+
+alias headers : : : : <include>. ;
+explicit headers ;
+
+# Make project ids of all libraries known.
+for local l in $(all-libraries)
+{
+    use-project /boost/$(l) : libs/$(l)/build ;
+}
+
+# This rule should be called from libraries' Jamfiles and will create two
+# targets, "install" and "stage", that will install or stage that library. The
+# --prefix option is respected, but --with and --without options, naturally, are
+# ignored.
+#
+# - libraries -- list of library targets to install.
+#
+rule boost-install ( libraries * )
+{
+    package.install install
+        : <dependency>/boost//install-proper-headers $(install-requirements)
+        : # No binaries
+        : $(libraries)
+        : # No headers, it is handled by the dependency.
+    ;
+
+    install stage : $(libraries) : <location>$(BOOST_STAGE_LOCATE) ;
+
+    module [ CALLER_MODULE ]
+    {
+        explicit stage ;
+        explicit install ;
+    }
+}
+
+headers =
+    # The .SUNWCCh files are present in tr1 include directory and have to be installed,
+    # see http://lists.boost.org/Archives/boost/2007/05/121430.php
+    [ path.glob-tree $(BOOST_ROOT)/boost : *.hpp *.ipp *.h *.inc *.SUNWCCh : CVS .svn ]
+    [ path.glob-tree $(BOOST_ROOT)/boost/compatibility/cpp_c_headers : c* : CVS .svn ] 
+    [ path.glob boost/tr1/tr1 : * : bcc32 sun CVS .svn ]
+    ;
+
+# Declare special top-level targets that build and install the desired variants
+# of the libraries.
+boostcpp.declare-targets $(all-libraries) : $(headers) ;
diff --git a/LICENSE_1_0.txt b/LICENSE_1_0.txt
new file mode 100644
index 0000000..36b7cd9
--- /dev/null
+++ b/LICENSE_1_0.txt
@@ -0,0 +1,23 @@
+Boost Software License - Version 1.0 - August 17th, 2003
+
+Permission is hereby granted, free of charge, to any person or organization
+obtaining a copy of the software and accompanying documentation covered by
+this license (the "Software") to use, reproduce, display, distribute,
+execute, and transmit the Software, and to prepare derivative works of the
+Software, and to permit third-parties to whom the Software is furnished to
+do so, all subject to the following:
+
+The copyright notices in the Software and this entire statement, including
+the above license grant, this restriction and the following disclaimer,
+must be included in all copies of the Software, in whole or in part, and
+all derivative works of the Software, unless such copies or derivative
+works are solely in the form of machine-executable object code generated by
+a source language processor.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/boost-build.jam b/boost-build.jam
new file mode 100644
index 0000000..8b87754
--- /dev/null
+++ b/boost-build.jam
@@ -0,0 +1,17 @@
+# Copyright (C) 2002-2003 David Abrahams.
+# Copyright (C) 2002-2003 Vladimir Prus.
+# Copyright (C) 2003,2007 Rene Rivera.
+# Use, modification and distribution are subject to the
+# Boost Software License, Version 1.0. (See accompanying file
+# LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#   This is the initial file loaded by Boost Jam when run from any Boost library
+# folder. It allows us to choose which Boost Build installation to use for
+# building Boost libraries. Unless explicitly selected using a command-line
+# option, the version included with the Boost library distribution is used (as
+# opposed to any other Boost Build version installed on the user's sytem).
+
+BOOST_ROOT = $(.boost-build-file:D) ;
+BOOST_BUILD = [ MATCH --boost-build=(.*) : $(ARGV) ] ;
+BOOST_BUILD ?= tools/build/v2 ;
+boost-build $(BOOST_BUILD) ;
diff --git a/boost.css b/boost.css
new file mode 100644
index 0000000..986c405
--- /dev/null
+++ b/boost.css
@@ -0,0 +1,66 @@
+/*=============================================================================
+    Copyright 2002 William E. Kempf
+    Distributed under the Boost Software License, Version 1.0. (See accompany-
+    ing file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+
+H1
+{
+    FONT-SIZE: 200%;
+    COLOR: #00008B;
+}
+H2
+{
+    FONT-SIZE: 150%;
+}
+H3
+{
+    FONT-SIZE: 125%;
+}
+H4
+{
+    FONT-SIZE: 108%;
+}
+BODY
+{
+    FONT-SIZE: 100%;
+    BACKGROUND-COLOR: #ffffff;
+    COLOR: #000000;
+}
+PRE
+{
+    MARGIN-LEFT: 2em;
+    FONT-FAMILY: Courier,
+                 monospace;
+}
+CODE
+{
+    FONT-FAMILY: Courier,
+                 monospace;
+}
+CODE.as_pre
+{
+    white-space: pre;
+}
+.index
+{
+    TEXT-ALIGN: left;
+}
+.page-index
+{
+    TEXT-ALIGN: left;
+}
+.definition
+{
+    TEXT-ALIGN: left;
+}
+.footnote
+{
+    FONT-SIZE: 66%;
+    VERTICAL-ALIGN: super;
+    TEXT-DECORATION: none;
+}
+.function-semantics
+{
+    CLEAR: left;
+}
\ No newline at end of file
diff --git a/boost.png b/boost.png
new file mode 100644
index 0000000..b4d51fc
--- /dev/null
+++ b/boost.png
Binary files differ
diff --git a/boost/accumulators/accumulators.hpp b/boost/accumulators/accumulators.hpp
new file mode 100644
index 0000000..55ee2f9
--- /dev/null
+++ b/boost/accumulators/accumulators.hpp
@@ -0,0 +1,27 @@
+///////////////////////////////////////////////////////////////////////////////
+/// \file accumulators.hpp
+/// Includes all of the Accumulators Framework
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_ACCUMULATORS_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_ACCUMULATORS_HPP_EAN_28_10_2005
+
+#include <boost/accumulators/framework/accumulator_set.hpp>
+#include <boost/accumulators/framework/accumulator_concept.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/external.hpp>
+#include <boost/accumulators/framework/features.hpp>
+#include <boost/accumulators/framework/parameters/accumulator.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/parameters/weight.hpp>
+#include <boost/accumulators/framework/parameters/weights.hpp>
+#include <boost/accumulators/framework/accumulators/external_accumulator.hpp>
+#include <boost/accumulators/framework/accumulators/droppable_accumulator.hpp>
+#include <boost/accumulators/framework/accumulators/reference_accumulator.hpp>
+#include <boost/accumulators/framework/accumulators/value_accumulator.hpp>
+
+#endif
diff --git a/boost/accumulators/accumulators_fwd.hpp b/boost/accumulators/accumulators_fwd.hpp
new file mode 100644
index 0000000..9986a53
--- /dev/null
+++ b/boost/accumulators/accumulators_fwd.hpp
@@ -0,0 +1,219 @@
+///////////////////////////////////////////////////////////////////////////////
+// accumulators_fwd.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_ACCUMULATORS_FWD_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_ACCUMULATORS_FWD_HPP_EAN_28_10_2005
+
+#include <boost/config.hpp>
+#include <boost/mpl/apply_fwd.hpp> // for mpl::na
+#include <boost/mpl/limits/vector.hpp>
+#include <boost/preprocessor/arithmetic/inc.hpp>
+#include <boost/preprocessor/repetition/enum_params_with_a_default.hpp>
+#include <boost/preprocessor/repetition/enum_trailing_params.hpp>
+#include <boost/preprocessor/repetition/enum_trailing_binary_params.hpp>
+#include <boost/preprocessor/repetition/repeat_from_to.hpp>
+#include <boost/accumulators/numeric/functional_fwd.hpp>
+
+#ifndef BOOST_ACCUMULATORS_MAX_FEATURES
+  /// The maximum number of accumulators that may be put in an accumulator_set.
+  /// Defaults to BOOST_MPL_LIMIT_VECTOR_SIZE (which defaults to 20).
+# define BOOST_ACCUMULATORS_MAX_FEATURES BOOST_MPL_LIMIT_VECTOR_SIZE
+#endif
+
+#if BOOST_ACCUMULATORS_MAX_FEATURES > BOOST_MPL_LIMIT_VECTOR_SIZE
+# error BOOST_ACCUMULATORS_MAX_FEATURES cannot be larger than BOOST_MPL_LIMIT_VECTOR_SIZE
+#endif
+
+#ifndef BOOST_ACCUMULATORS_MAX_ARGS
+  /// The maximum number of arguments that may be specified to an accumulator_set's
+  /// accumulation function. Defaults to 15.
+# define BOOST_ACCUMULATORS_MAX_ARGS 15
+#endif
+
+#if BOOST_WORKAROUND(__GNUC__, == 3) \
+ || BOOST_WORKAROUND(__EDG_VERSION__, BOOST_TESTED_AT(306))
+# define BOOST_ACCUMULATORS_BROKEN_CONST_OVERLOADS
+#endif
+
+#ifdef BOOST_ACCUMULATORS_BROKEN_CONST_OVERLOADS
+# include <boost/utility/enable_if.hpp>
+# include <boost/type_traits/is_const.hpp>
+# define BOOST_ACCUMULATORS_PROTO_DISABLE_IF_IS_CONST(T)\
+    , typename boost::disable_if<boost::is_const<T> >::type * = 0
+#else
+# define BOOST_ACCUMULATORS_PROTO_DISABLE_IF_IS_CONST(T)
+#endif
+
+#define BOOST_ACCUMULATORS_GCC_VERSION                                                              \
+  (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
+
+namespace boost { namespace accumulators
+{
+
+///////////////////////////////////////////////////////////////////////////////
+// Named parameters tags
+//
+namespace tag
+{
+    struct sample;
+    struct weight;
+    struct accumulator;
+    struct weights;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// User-level features
+//
+namespace tag
+{
+    template<typename ValueType, typename Tag>
+    struct value;
+
+    template<typename Tag>
+    struct value_tag;
+
+    template<typename Referent, typename Tag>
+    struct reference;
+
+    template<typename Tag>
+    struct reference_tag;
+
+    template<typename Type, typename Tag = void, typename AccumulatorSet = void>
+    struct external;
+
+    template<typename Feature>
+    struct droppable;
+}
+
+template<typename Accumulator>
+struct droppable_accumulator_base;
+
+template<typename Accumulator>
+struct droppable_accumulator;
+
+template<typename Accumulator>
+struct with_cached_result;
+
+template<typename Sample, typename Features, typename Weight = void>
+struct accumulator_set;
+
+template<typename Feature>
+struct extractor;
+
+template<typename Feature>
+struct feature_of;
+
+template<typename Feature>
+struct as_feature;
+
+template<typename Feature>
+struct as_weighted_feature;
+
+template<BOOST_PP_ENUM_PARAMS_WITH_A_DEFAULT(BOOST_ACCUMULATORS_MAX_FEATURES, typename Feature, mpl::na)>
+struct depends_on;
+
+template<BOOST_PP_ENUM_PARAMS_WITH_A_DEFAULT(BOOST_ACCUMULATORS_MAX_FEATURES, typename Feature, mpl::na)>
+struct features;
+
+template<typename Feature, typename AccumulatorSet>
+typename mpl::apply<AccumulatorSet, Feature>::type const &
+find_accumulator(AccumulatorSet const &acc);
+
+template<typename Feature, typename AccumulatorSet>
+typename mpl::apply<AccumulatorSet, Feature>::type::result_type
+extract_result(AccumulatorSet const &acc);
+
+template<typename Feature, typename AccumulatorSet, typename A1>
+typename mpl::apply<AccumulatorSet, Feature>::type::result_type
+extract_result(AccumulatorSet const &acc, A1 const &a1);
+
+// ... other overloads generated by Boost.Preprocessor:
+
+/// INTERNAL ONLY
+///
+#define BOOST_ACCUMULATORS_EXTRACT_RESULT_FWD(z, n, _)                      \
+    template<                                                               \
+        typename Feature                                                    \
+      , typename AccumulatorSet                                             \
+        BOOST_PP_ENUM_TRAILING_PARAMS_Z(z, n, typename A)                   \
+    >                                                                       \
+    typename mpl::apply<AccumulatorSet, Feature>::type::result_type         \
+    extract_result(                                                         \
+        AccumulatorSet const &acc                                           \
+        BOOST_PP_ENUM_TRAILING_BINARY_PARAMS_Z(z, n, A, const &a)           \
+    );
+
+/// INTERNAL ONLY
+///
+BOOST_PP_REPEAT_FROM_TO(
+    2
+  , BOOST_PP_INC(BOOST_ACCUMULATORS_MAX_ARGS)
+  , BOOST_ACCUMULATORS_EXTRACT_RESULT_FWD
+  , _
+)
+
+#ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
+template<typename Feature, typename AccumulatorSet, typename A1, typename A2 ...>
+typename mpl::apply<AccumulatorSet, Feature>::type::result_type
+extract_result(AccumulatorSet const &acc, A1 const &a1, A2 const &a2 ...);
+#endif
+
+namespace impl
+{
+    using namespace numeric::operators;
+
+    template<typename Accumulator, typename Tag>
+    struct external_impl;
+}
+
+namespace detail
+{
+    template<typename Accumulator>
+    struct feature_tag;
+
+    template<typename Feature, typename Sample, typename Weight>
+    struct to_accumulator;
+
+    struct accumulator_set_base;
+
+    template<typename T>
+    struct is_accumulator_set;
+
+    inline void ignore_variable(void const *) {}
+
+  #define BOOST_ACCUMULATORS_IGNORE_GLOBAL(X)\
+    namespace detail { inline void BOOST_PP_CAT(ignore_, X)() { boost::accumulators::detail::ignore_variable(&X); } }
+}
+
+}} // namespace boost::accumulators
+
+// For defining boost::parameter keywords that can be inherited from to
+// get a nested, class-scoped keyword with the requested alias
+#define BOOST_PARAMETER_NESTED_KEYWORD(tag_namespace, name, alias)                                  \
+    namespace tag_namespace                                                                         \
+    {                                                                                               \
+        template<int Dummy = 0>                                                                     \
+        struct name ## _                                                                            \
+        {                                                                                           \
+            static char const* keyword_name()                                                       \
+            {                                                                                       \
+                return #name;                                                                       \
+            }                                                                                       \
+            static ::boost::parameter::keyword<name ## _<Dummy> > &alias;                           \
+        };                                                                                          \
+        template<int Dummy>                                                                         \
+        ::boost::parameter::keyword<name ## _<Dummy> > &name ## _<Dummy>::alias =                   \
+        ::boost::parameter::keyword<name ## _<Dummy> >::get();                                      \
+        typedef name ## _ <> name;                                                                  \
+    }                                                                                               \
+    namespace                                                                                       \
+    {                                                                                               \
+        ::boost::parameter::keyword<tag_namespace::name> &name =                                    \
+        ::boost::parameter::keyword<tag_namespace::name>::get();                                    \
+    }
+
+#endif
diff --git a/boost/accumulators/framework/accumulator_base.hpp b/boost/accumulators/framework/accumulator_base.hpp
new file mode 100644
index 0000000..52c520d
--- /dev/null
+++ b/boost/accumulators/framework/accumulator_base.hpp
@@ -0,0 +1,65 @@
+///////////////////////////////////////////////////////////////////////////////
+// accumulator_base.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATORS_BASE_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATORS_BASE_HPP_EAN_28_10_2005
+
+#include <boost/mpl/placeholders.hpp>
+#include <boost/mpl/joint_view.hpp>
+#include <boost/mpl/single_view.hpp>
+#include <boost/mpl/fold.hpp>
+#include <boost/mpl/contains.hpp>
+#include <boost/mpl/empty_sequence.hpp>
+#include <boost/accumulators/framework/accumulator_concept.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace detail
+{
+    typedef void void_;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// dont_care
+//
+struct dont_care
+{
+    template<typename Args>
+    dont_care(Args const &)
+    {
+    }
+};
+
+///////////////////////////////////////////////////////////////////////////////
+// accumulator_base
+//
+struct accumulator_base
+{
+    // hidden if defined in derived classes
+    detail::void_ operator ()(dont_care)
+    {
+    }
+
+    typedef mpl::false_ is_droppable;
+
+    detail::void_ add_ref(dont_care)
+    {
+    }
+
+    detail::void_ drop(dont_care)
+    {
+    }
+
+    detail::void_ on_drop(dont_care)
+    {
+    }
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/framework/accumulator_concept.hpp b/boost/accumulators/framework/accumulator_concept.hpp
new file mode 100644
index 0000000..492357e
--- /dev/null
+++ b/boost/accumulators/framework/accumulator_concept.hpp
@@ -0,0 +1,29 @@
+///////////////////////////////////////////////////////////////////////////////
+// accumulator_concept.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATOR_CONCEPT_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATOR_CONCEPT_HPP_EAN_28_10_2005
+
+#include <boost/concept_check.hpp>
+
+namespace boost { namespace accumulators
+{
+
+template<typename Stat>
+struct accumulator_concept
+{
+    void constraints()
+    {
+        // TODO: define the stat concept
+    }
+
+    Stat stat;
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/framework/accumulator_set.hpp b/boost/accumulators/framework/accumulator_set.hpp
new file mode 100644
index 0000000..ed1ceb1
--- /dev/null
+++ b/boost/accumulators/framework/accumulator_set.hpp
@@ -0,0 +1,401 @@
+///////////////////////////////////////////////////////////////////////////////
+// accumulator_set.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATOR_SET_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATOR_SET_HPP_EAN_28_10_2005
+
+#include <boost/version.hpp>
+#include <boost/mpl/apply.hpp>
+#include <boost/mpl/assert.hpp>
+#include <boost/mpl/protect.hpp>
+#include <boost/mpl/identity.hpp>
+#include <boost/mpl/is_sequence.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/type_traits/is_base_and_derived.hpp>
+#include <boost/parameter/parameters.hpp>
+#include <boost/preprocessor/repetition/repeat_from_to.hpp>
+#include <boost/preprocessor/repetition/enum_binary_params.hpp>
+#include <boost/accumulators/accumulators_fwd.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/framework/accumulator_concept.hpp>
+#include <boost/accumulators/framework/parameters/accumulator.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/accumulators/external_accumulator.hpp>
+#include <boost/accumulators/framework/accumulators/droppable_accumulator.hpp>
+#include <boost/fusion/include/any.hpp>
+#include <boost/fusion/include/find_if.hpp>
+#include <boost/fusion/include/for_each.hpp>
+#include <boost/fusion/include/filter_view.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace detail
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // accumulator_visitor
+    //   wrap a boost::parameter argument pack in a Fusion extractor object
+    template<typename Args>
+    struct accumulator_visitor
+    {
+        explicit accumulator_visitor(Args const &a)
+          : args(a)
+        {
+        }
+
+        template<typename Accumulator>
+        void operator ()(Accumulator &accumulator) const
+        {
+            accumulator(this->args);
+        }
+
+    private:
+        accumulator_visitor &operator =(accumulator_visitor const &);
+        Args const &args;
+    };
+
+    template<typename Args>
+    inline accumulator_visitor<Args> const make_accumulator_visitor(Args const &args)
+    {
+        return accumulator_visitor<Args>(args);
+    }
+
+    typedef
+        parameter::parameters<
+            parameter::required<tag::accumulator>
+          , parameter::optional<tag::sample>
+          // ... and others which are not specified here...
+        >
+    accumulator_params;
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // accumulator_set_base
+    struct accumulator_set_base
+    {
+    };
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // is_accumulator_set
+    template<typename T>
+    struct is_accumulator_set
+      : is_base_and_derived<accumulator_set_base, T>
+    {
+    };
+
+} // namespace detail
+
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable: 4355) // warning C4355: 'this' : used in base member initializer list
+#endif
+
+///////////////////////////////////////////////////////////////////////////////
+/// \brief A set of accumulators.
+///
+/// accumulator_set resolves the dependencies between features and ensures that
+/// the accumulators in the set are updated in the proper order.
+///
+/// acccumulator_set provides a general mechanism to visit the accumulators
+/// in the set in order, with or without a filter. You can also fetch a reference
+/// to an accumulator that corresponds to a feature.
+///
+template<typename Sample, typename Features, typename Weight>
+struct accumulator_set
+  : detail::accumulator_set_base
+{
+    typedef Sample sample_type;     ///< The type of the samples that will be accumulated
+    typedef Features features_type; ///< An MPL sequence of the features that should be accumulated.
+    typedef Weight weight_type;     ///< The type of the weight parameter. Must be a scalar. Defaults to void.
+
+    /// INTERNAL ONLY
+    ///
+    typedef
+        typename detail::make_accumulator_tuple<
+            Features
+          , Sample
+          , Weight
+        >::type
+    accumulators_mpl_vector;
+
+    // generate a fusion::list of accumulators
+    /// INTERNAL ONLY
+    ///
+    typedef
+        typename detail::meta::make_acc_list<
+            accumulators_mpl_vector
+        >::type
+    accumulators_type;
+
+    /// INTERNAL ONLY
+    ///
+    //BOOST_MPL_ASSERT((mpl::is_sequence<accumulators_type>));
+
+    ///////////////////////////////////////////////////////////////////////////////
+    /// default-construct all contained accumulators
+    accumulator_set()
+      : accumulators(
+            detail::make_acc_list(
+                accumulators_mpl_vector()
+              , detail::accumulator_params()(*this)
+            )
+        )
+    {
+        // Add-ref the Features that the user has specified
+        this->template visit_if<detail::contains_feature_of_<Features> >(
+            detail::make_add_ref_visitor(detail::accumulator_params()(*this))
+        );
+    }
+
+    /// \overload
+    ///
+    /// \param a1 Optional named parameter to be passed to all the accumulators
+    template<typename A1>
+    explicit accumulator_set(A1 const &a1)
+      : accumulators(
+            detail::make_acc_list(
+                accumulators_mpl_vector()
+              , detail::accumulator_params()(*this, a1)
+            )
+        )
+    {
+        // Add-ref the Features that the user has specified
+        this->template visit_if<detail::contains_feature_of_<Features> >(
+            detail::make_add_ref_visitor(detail::accumulator_params()(*this))
+        );
+    }
+
+    // ... other overloads generated by Boost.Preprocessor:
+
+    /// INTERNAL ONLY
+    ///
+#define BOOST_ACCUMULATORS_ACCUMULATOR_SET_CTOR(z, n, _)                                \
+    template<BOOST_PP_ENUM_PARAMS_Z(z, n, typename A)>                                  \
+    accumulator_set(BOOST_PP_ENUM_BINARY_PARAMS_Z(z, n, A, const &a))                   \
+      : accumulators(                                                                   \
+            detail::make_acc_list(                                                      \
+                accumulators_mpl_vector()                                               \
+              , detail::accumulator_params()(                                           \
+                    *this BOOST_PP_ENUM_TRAILING_PARAMS_Z(z, n, a)                      \
+                )                                                                       \
+            )                                                                           \
+        )                                                                               \
+    {                                                                                   \
+        /* Add-ref the Features that the user has specified */                          \
+        this->template visit_if<detail::contains_feature_of_<Features> >(               \
+            detail::make_add_ref_visitor(detail::accumulator_params()(*this))           \
+        );                                                                              \
+    }
+
+    /// INTERNAL ONLY
+    ///
+    BOOST_PP_REPEAT_FROM_TO(
+        2
+      , BOOST_PP_INC(BOOST_ACCUMULATORS_MAX_ARGS)
+      , BOOST_ACCUMULATORS_ACCUMULATOR_SET_CTOR
+      , _
+    )
+
+    #ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
+    /// \overload
+    ///
+    template<typename A1, typename A2, ...>
+    accumulator_set(A1 const &a1, A2 const &a2, ...);
+    #endif
+
+    // ... other overloads generated by Boost.Preprocessor below ...
+
+    ///////////////////////////////////////////////////////////////////////////////
+    /// Visitation
+    /// \param func UnaryFunction which is invoked with each accumulator in turn.
+    template<typename UnaryFunction>
+    void visit(UnaryFunction const &func)
+    {
+        fusion::for_each(this->accumulators, func);
+    }
+
+    ///////////////////////////////////////////////////////////////////////////////
+    /// Conditional visitation
+    /// \param func UnaryFunction which is invoked with each accumulator in turn,
+    ///     provided the accumulator satisfies the MPL predicate FilterPred.
+    template<typename FilterPred, typename UnaryFunction>
+    void visit_if(UnaryFunction const &func)
+    {
+        fusion::filter_view<accumulators_type, FilterPred> filtered_accs(this->accumulators);
+        fusion::for_each(filtered_accs, func);
+    }
+    
+    ///////////////////////////////////////////////////////////////////////////////
+    /// The return type of the operator() overloads is void.
+    typedef void result_type;
+
+    ///////////////////////////////////////////////////////////////////////////////
+    /// Accumulation
+    /// \param a1 Optional named parameter to be passed to all the accumulators
+    void operator ()()
+    {
+        this->visit(
+            detail::make_accumulator_visitor(
+                detail::accumulator_params()(*this)
+            )
+        );
+    }
+
+    template<typename A1>
+    void operator ()(A1 const &a1)
+    {
+        this->visit(
+            detail::make_accumulator_visitor(
+                detail::accumulator_params()(*this, a1)
+            )
+        );
+    }
+
+    // ... other overloads generated by Boost.Preprocessor:
+
+    /// INTERNAL ONLY
+    ///
+#define BOOST_ACCUMULATORS_ACCUMULATOR_SET_FUN_OP(z, n, _)                              \
+    template<BOOST_PP_ENUM_PARAMS_Z(z, n, typename A)>                                  \
+    void operator ()(BOOST_PP_ENUM_BINARY_PARAMS_Z(z, n, A, const &a))                  \
+    {                                                                                   \
+        this->visit(                                                                    \
+            detail::make_accumulator_visitor(                                           \
+                detail::accumulator_params()(                                           \
+                    *this BOOST_PP_ENUM_TRAILING_PARAMS_Z(z, n, a)                      \
+                )                                                                       \
+            )                                                                           \
+        );                                                                              \
+    }
+
+    /// INTERNAL ONLY
+    ///
+    BOOST_PP_REPEAT_FROM_TO(
+        2
+      , BOOST_PP_INC(BOOST_ACCUMULATORS_MAX_ARGS)
+      , BOOST_ACCUMULATORS_ACCUMULATOR_SET_FUN_OP
+      , _
+    )
+
+    #ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
+    /// \overload
+    ///
+    template<typename A1, typename A2, ...>
+    void operator ()(A1 const &a1, A2 const &a2, ...);
+    #endif
+
+    ///////////////////////////////////////////////////////////////////////////////
+    /// Extraction
+    template<typename Feature>
+    struct apply
+      : fusion::result_of::value_of<
+            typename fusion::result_of::find_if<
+                accumulators_type
+              , detail::matches_feature<Feature>
+            >::type
+        >
+    {
+    };
+
+    ///////////////////////////////////////////////////////////////////////////////
+    /// Extraction
+    template<typename Feature>
+    typename apply<Feature>::type &extract()
+    {
+        return *fusion::find_if<detail::matches_feature<Feature> >(this->accumulators);
+    }
+
+    /// \overload
+    template<typename Feature>
+    typename apply<Feature>::type const &extract() const
+    {
+        return *fusion::find_if<detail::matches_feature<Feature> >(this->accumulators);
+    }
+
+    ///////////////////////////////////////////////////////////////////////////////
+    /// Drop
+    template<typename Feature>
+    void drop()
+    {
+        // You can only drop the features that you have specified explicitly
+        typedef typename apply<Feature>::type the_accumulator;
+        BOOST_MPL_ASSERT((detail::contains_feature_of<Features, the_accumulator>));
+
+        typedef
+            typename feature_of<typename as_feature<Feature>::type>::type
+        the_feature;
+
+        (*fusion::find_if<detail::matches_feature<Feature> >(this->accumulators))
+            .drop(detail::accumulator_params()(*this));
+
+        // Also drop accumulators that this feature depends on
+        typedef typename the_feature::dependencies dependencies;
+        this->template visit_if<detail::contains_feature_of_<dependencies> >(
+            detail::make_drop_visitor(detail::accumulator_params()(*this))
+        );
+    }
+
+private:
+
+    accumulators_type accumulators;
+};
+
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
+///////////////////////////////////////////////////////////////////////////////
+// find_accumulator
+//   find an accumulator in an accumulator_set corresponding to a feature
+template<typename Feature, typename AccumulatorSet>
+typename mpl::apply<AccumulatorSet, Feature>::type &
+find_accumulator(AccumulatorSet &acc BOOST_ACCUMULATORS_PROTO_DISABLE_IF_IS_CONST(AccumulatorSet))
+{
+    return acc.template extract<Feature>();
+}
+
+/// \overload
+template<typename Feature, typename AccumulatorSet>
+typename mpl::apply<AccumulatorSet, Feature>::type const &
+find_accumulator(AccumulatorSet const &acc)
+{
+    return acc.template extract<Feature>();
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract_result
+//   extract a result from an accumulator set
+/// INTERNAL ONLY
+///
+#define BOOST_ACCUMULATORS_EXTRACT_RESULT_FUN(z, n, _)                      \
+    template<                                                               \
+        typename Feature                                                    \
+      , typename AccumulatorSet                                             \
+        BOOST_PP_ENUM_TRAILING_PARAMS_Z(z, n, typename A)                   \
+    >                                                                       \
+    typename mpl::apply<AccumulatorSet, Feature>::type::result_type         \
+    extract_result(                                                         \
+        AccumulatorSet const &acc                                           \
+        BOOST_PP_ENUM_TRAILING_BINARY_PARAMS_Z(z, n, A, const &a)           \
+    )                                                                       \
+    {                                                                       \
+        return find_accumulator<Feature>(acc).result(                       \
+            detail::accumulator_params()(                                   \
+                acc                                                         \
+                BOOST_PP_ENUM_TRAILING_PARAMS_Z(z, n, a)                    \
+            )                                                               \
+        );                                                                  \
+    }
+
+BOOST_PP_REPEAT(
+    BOOST_PP_INC(BOOST_ACCUMULATORS_MAX_ARGS)
+  , BOOST_ACCUMULATORS_EXTRACT_RESULT_FUN
+  , _
+)
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/framework/accumulators/droppable_accumulator.hpp b/boost/accumulators/framework/accumulators/droppable_accumulator.hpp
new file mode 100644
index 0000000..c0f512f
--- /dev/null
+++ b/boost/accumulators/framework/accumulators/droppable_accumulator.hpp
@@ -0,0 +1,317 @@
+///////////////////////////////////////////////////////////////////////////////
+// droppable_accumulator.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATORS_DROPPABLE_ACCUMULATOR_HPP_EAN_13_12_2005
+#define BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATORS_DROPPABLE_ACCUMULATOR_HPP_EAN_13_12_2005
+
+#include <new>
+#include <boost/assert.hpp>
+#include <boost/mpl/apply.hpp>
+#include <boost/aligned_storage.hpp>
+#include <boost/accumulators/framework/depends_on.hpp> // for feature_of
+#include <boost/accumulators/framework/parameters/accumulator.hpp> // for accumulator
+
+namespace boost { namespace accumulators
+{
+
+    template<typename Accumulator>
+    struct droppable_accumulator;
+
+    namespace detail
+    {
+        ///////////////////////////////////////////////////////////////////////////////
+        // add_ref_visitor
+        //   a fusion function object for add_ref'ing accumulators
+        template<typename Args>
+        struct add_ref_visitor
+        {
+            explicit add_ref_visitor(Args const &args)
+              : args_(args)
+            {
+            }
+
+            template<typename Accumulator>
+            void operator ()(Accumulator &acc) const
+            {
+                typedef typename Accumulator::feature_tag::dependencies dependencies;
+
+                acc.add_ref(this->args_);
+
+                // Also add_ref accumulators that this feature depends on
+                this->args_[accumulator].template
+                    visit_if<detail::contains_feature_of_<dependencies> >(
+                        *this
+                );
+            }
+
+        private:
+            add_ref_visitor &operator =(add_ref_visitor const &);
+            Args const &args_;
+        };
+
+        template<typename Args>
+        add_ref_visitor<Args> make_add_ref_visitor(Args const &args)
+        {
+            return add_ref_visitor<Args>(args);
+        }
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // drop_visitor
+        //   a fusion function object for dropping accumulators
+        template<typename Args>
+        struct drop_visitor
+        {
+            explicit drop_visitor(Args const &args)
+              : args_(args)
+            {
+            }
+
+            template<typename Accumulator>
+            void operator ()(Accumulator &acc) const
+            {
+                if(typename Accumulator::is_droppable())
+                {
+                    typedef typename Accumulator::feature_tag::dependencies dependencies;
+
+                    acc.drop(this->args_);
+                    // Also drop accumulators that this feature depends on
+                    this->args_[accumulator].template
+                        visit_if<detail::contains_feature_of_<dependencies> >(
+                            *this
+                    );
+                }
+            }
+
+        private:
+            drop_visitor &operator =(drop_visitor const &);
+            Args const &args_;
+        };
+
+        template<typename Args>
+        drop_visitor<Args> make_drop_visitor(Args const &args)
+        {
+            return drop_visitor<Args>(args);
+        }
+    }
+
+    //////////////////////////////////////////////////////////////////////////
+    // droppable_accumulator_base
+    template<typename Accumulator>
+    struct droppable_accumulator_base
+      : Accumulator
+    {
+        typedef droppable_accumulator_base base;
+        typedef mpl::true_ is_droppable;
+        typedef typename Accumulator::result_type result_type;
+
+        template<typename Args>
+        droppable_accumulator_base(Args const &args)
+          : Accumulator(args)
+          , ref_count_(0)
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            if(!this->is_dropped())
+            {
+                this->Accumulator::operator ()(args);
+            }
+        }
+
+        template<typename Args>
+        void add_ref(Args const &)
+        {
+            ++this->ref_count_;
+        }
+
+        template<typename Args>
+        void drop(Args const &args)
+        {
+            BOOST_ASSERT(0 < this->ref_count_);
+            if(1 == this->ref_count_)
+            {
+                static_cast<droppable_accumulator<Accumulator> *>(this)->on_drop(args);
+            }
+            --this->ref_count_;
+        }
+
+        bool is_dropped() const
+        {
+            return 0 == this->ref_count_;
+        }
+
+    private:
+        int ref_count_;
+    };
+
+    //////////////////////////////////////////////////////////////////////////
+    // droppable_accumulator
+    //   this can be specialized for any type that needs special handling
+    template<typename Accumulator>
+    struct droppable_accumulator
+      : droppable_accumulator_base<Accumulator>
+    {
+        template<typename Args>
+        droppable_accumulator(Args const &args)
+          : droppable_accumulator::base(args)
+        {
+        }
+    };
+
+    //////////////////////////////////////////////////////////////////////////
+    // with_cached_result
+    template<typename Accumulator>
+    struct with_cached_result
+      : Accumulator
+    {
+        typedef typename Accumulator::result_type result_type;
+
+        template<typename Args>
+        with_cached_result(Args const &args)
+          : Accumulator(args)
+          , cache()
+        {
+        }
+
+        with_cached_result(with_cached_result const &that)
+          : Accumulator(*static_cast<Accumulator const *>(&that))
+          , cache()
+        {
+            if(that.has_result())
+            {
+                this->set(that.get());
+            }
+        }
+
+        ~with_cached_result()
+        {
+            // Since this is a base class of droppable_accumulator_base,
+            // this destructor is called before any of droppable_accumulator_base's
+            // members get cleaned up, including is_dropped, so the following
+            // call to has_result() is valid.
+            if(this->has_result())
+            {
+                this->get().~result_type();
+            }
+        }
+
+        template<typename Args>
+        void on_drop(Args const &args)
+        {
+            // cache the result at the point this calcuation was dropped
+            BOOST_ASSERT(!this->has_result());
+            this->set(this->Accumulator::result(args));
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            return this->has_result() ? this->get() : this->Accumulator::result(args);
+        }
+
+    private:
+        with_cached_result &operator =(with_cached_result const &);
+
+        void set(result_type const &r)
+        {
+            ::new(this->cache.address()) result_type(r);
+        }
+
+        result_type const &get() const
+        {
+            return *static_cast<result_type const *>(this->cache.address());
+        }
+
+        bool has_result() const
+        {
+            typedef with_cached_result<Accumulator> this_type;
+            typedef droppable_accumulator_base<this_type> derived_type;
+            return static_cast<derived_type const *>(this)->is_dropped();
+        }
+
+        aligned_storage<sizeof(result_type)> cache;
+    };
+
+    namespace tag
+    {
+        template<typename Feature>
+        struct as_droppable
+        {
+            typedef droppable<Feature> type;
+        };
+
+        template<typename Feature>
+        struct as_droppable<droppable<Feature> >
+        {
+            typedef droppable<Feature> type;
+        };
+
+        //////////////////////////////////////////////////////////////////////////
+        // droppable
+        template<typename Feature>
+        struct droppable
+          : as_feature<Feature>::type
+        {
+            typedef typename as_feature<Feature>::type feature_type;
+            typedef typename feature_type::dependencies tmp_dependencies_;
+
+            typedef
+                typename mpl::transform<
+                    typename feature_type::dependencies
+                  , as_droppable<mpl::_1>
+                >::type
+            dependencies;
+
+            struct impl
+            {
+                template<typename Sample, typename Weight>
+                struct apply
+                {
+                    typedef
+                        droppable_accumulator<
+                            typename mpl::apply2<typename feature_type::impl, Sample, Weight>::type
+                        >
+                    type;
+                };
+            };
+        };
+    }
+
+    // make droppable<tag::feature(modifier)> work
+    template<typename Feature>
+    struct as_feature<tag::droppable<Feature> >
+    {
+        typedef tag::droppable<typename as_feature<Feature>::type> type;
+    };
+
+    // make droppable<tag::mean> work with non-void weights (should become
+    // droppable<tag::weighted_mean>
+    template<typename Feature>
+    struct as_weighted_feature<tag::droppable<Feature> >
+    {
+        typedef tag::droppable<typename as_weighted_feature<Feature>::type> type;
+    };
+
+    // for the purposes of feature-based dependency resolution,
+    // droppable<Foo> provides the same feature as Foo
+    template<typename Feature>
+    struct feature_of<tag::droppable<Feature> >
+      : feature_of<Feature>
+    {
+    };
+
+    // Note: Usually, the extractor is pulled into the accumulators namespace with
+    // a using directive, not the tag. But the droppable<> feature doesn't have an
+    // extractor, so we can put the droppable tag in the accumulators namespace
+    // without fear of a name conflict.
+    using tag::droppable;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/framework/accumulators/external_accumulator.hpp b/boost/accumulators/framework/accumulators/external_accumulator.hpp
new file mode 100644
index 0000000..71dce42
--- /dev/null
+++ b/boost/accumulators/framework/accumulators/external_accumulator.hpp
@@ -0,0 +1,108 @@
+///////////////////////////////////////////////////////////////////////////////
+// external_accumulator.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATORS_EXTERNAL_ACCUMULATOR_HPP_EAN_01_12_2005
+#define BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATORS_EXTERNAL_ACCUMULATOR_HPP_EAN_01_12_2005
+
+#include <boost/mpl/placeholders.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/depends_on.hpp> // for feature_tag
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/accumulators/reference_accumulator.hpp>
+
+namespace boost { namespace accumulators { namespace impl
+{
+
+    //////////////////////////////////////////////////////////////////////////
+    // external_impl
+    /// INTERNAL ONLY
+    ///
+    template<typename Accumulator, typename Tag>
+    struct external_impl
+      : accumulator_base
+    {
+        typedef typename Accumulator::result_type result_type;
+        typedef typename detail::feature_tag<Accumulator>::type feature_tag;
+
+        external_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            return this->extract_(args, args[parameter::keyword<Tag>::get() | 0]);
+        }
+
+    private:
+
+        template<typename Args>
+        static result_type extract_(Args const &args, int)
+        {
+            // No named parameter passed to the extractor. Maybe the external
+            // feature is held by reference<>.
+            extractor<feature_tag> extract;
+            return extract(accumulators::reference_tag<Tag>(args));
+        }
+
+        template<typename Args, typename AccumulatorSet>
+        static result_type extract_(Args const &, AccumulatorSet const &acc)
+        {
+            // OK, a named parameter for this external feature was passed to the
+            // extractor, so use that.
+            extractor<feature_tag> extract;
+            return extract(acc);
+        }
+    };
+
+} // namespace impl
+
+namespace tag
+{
+    //////////////////////////////////////////////////////////////////////////
+    // external
+    template<typename Feature, typename Tag, typename AccumulatorSet>
+    struct external
+      : depends_on<reference<AccumulatorSet, Tag> >
+    {
+        typedef
+            accumulators::impl::external_impl<
+                detail::to_accumulator<Feature, mpl::_1, mpl::_2>
+              , Tag
+            >
+        impl;
+    };
+
+    template<typename Feature, typename Tag>
+    struct external<Feature, Tag, void>
+      : depends_on<>
+    {
+        typedef
+            accumulators::impl::external_impl<
+                detail::to_accumulator<Feature, mpl::_1, mpl::_2>
+              , Tag
+            >
+        impl;
+    };
+}
+
+// for the purposes of feature-based dependency resolution,
+// external_accumulator<Feature, Tag> provides the same feature as Feature
+template<typename Feature, typename Tag, typename AccumulatorSet>
+struct feature_of<tag::external<Feature, Tag, AccumulatorSet> >
+  : feature_of<Feature>
+{
+};
+
+// Note: Usually, the extractor is pulled into the accumulators namespace with
+// a using directive, not the tag. But the external<> feature doesn't have an
+// extractor, so we can put the external tag in the accumulators namespace
+// without fear of a name conflict.
+using tag::external;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/framework/accumulators/reference_accumulator.hpp b/boost/accumulators/framework/accumulators/reference_accumulator.hpp
new file mode 100644
index 0000000..bf4252c
--- /dev/null
+++ b/boost/accumulators/framework/accumulators/reference_accumulator.hpp
@@ -0,0 +1,89 @@
+///////////////////////////////////////////////////////////////////////////////
+// reference_accumulator.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATORS_REFERENCE_ACCUMULATOR_HPP_EAN_03_23_2006
+#define BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATORS_REFERENCE_ACCUMULATOR_HPP_EAN_03_23_2006
+
+#include <boost/ref.hpp>
+#include <boost/mpl/always.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/accumulators/framework/depends_on.hpp> // for feature_tag
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    //////////////////////////////////////////////////////////////////////////
+    // reference_accumulator_impl
+    //
+    template<typename Referent, typename Tag>
+    struct reference_accumulator_impl
+      : accumulator_base
+    {
+        typedef Referent &result_type;
+
+        template<typename Args>
+        reference_accumulator_impl(Args const &args)
+          : ref(args[parameter::keyword<Tag>::get()])
+        {
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->ref;
+        }
+
+    private:
+        reference_wrapper<Referent> ref;
+    };
+} // namespace impl
+
+namespace tag
+{
+    //////////////////////////////////////////////////////////////////////////
+    // reference_tag
+    template<typename Tag>
+    struct reference_tag
+    {
+    };
+
+    //////////////////////////////////////////////////////////////////////////
+    // reference
+    template<typename Referent, typename Tag>
+    struct reference
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef mpl::always<accumulators::impl::reference_accumulator_impl<Referent, Tag> > impl;
+    };
+}
+
+namespace extract
+{
+    BOOST_ACCUMULATORS_DEFINE_EXTRACTOR(tag, reference, (typename)(typename))
+    BOOST_ACCUMULATORS_DEFINE_EXTRACTOR(tag, reference_tag, (typename))
+}
+
+using extract::reference;
+using extract::reference_tag;
+
+// Map all reference<V,T> features to reference_tag<T> so
+// that references can be extracted using reference_tag<T>
+// without specifying the referent type.
+template<typename ValueType, typename Tag>
+struct feature_of<tag::reference<ValueType, Tag> >
+  : feature_of<tag::reference_tag<Tag> >
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/framework/accumulators/value_accumulator.hpp b/boost/accumulators/framework/accumulators/value_accumulator.hpp
new file mode 100644
index 0000000..02bf7f3
--- /dev/null
+++ b/boost/accumulators/framework/accumulators/value_accumulator.hpp
@@ -0,0 +1,89 @@
+///////////////////////////////////////////////////////////////////////////////
+// value_accumulator.hpp
+//
+//  Copyright 2005 Eric Niebler, Daniel Egloff. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATORS_VALUE_ACCUMULATOR_HPP_EAN_03_23_2006
+#define BOOST_ACCUMULATORS_FRAMEWORK_ACCUMULATORS_VALUE_ACCUMULATOR_HPP_EAN_03_23_2006
+
+#include <boost/mpl/always.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/accumulators/framework/depends_on.hpp> // for feature_tag
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+
+    //////////////////////////////////////////////////////////////////////////
+    // value_accumulator_impl
+    template<typename ValueType, typename Tag>
+    struct value_accumulator_impl
+      : accumulator_base
+    {
+        typedef ValueType result_type;
+
+        template<typename Args>
+        value_accumulator_impl(Args const &args)
+          : val(args[parameter::keyword<Tag>::get()])
+        {
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->val;
+        }
+
+    private:
+        ValueType val;
+    };
+
+} // namespace impl
+
+namespace tag
+{
+    //////////////////////////////////////////////////////////////////////////
+    // value_tag
+    template<typename Tag>
+    struct value_tag
+    {
+    };
+
+    //////////////////////////////////////////////////////////////////////////
+    // value
+    template<typename ValueType, typename Tag>
+    struct value
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef mpl::always<accumulators::impl::value_accumulator_impl<ValueType, Tag> > impl;
+    };
+}
+
+namespace extract
+{
+    BOOST_ACCUMULATORS_DEFINE_EXTRACTOR(tag, value, (typename)(typename))
+    BOOST_ACCUMULATORS_DEFINE_EXTRACTOR(tag, value_tag, (typename))
+}
+
+using extract::value;
+using extract::value_tag;
+
+// Map all value<V,T> features to value_tag<T> so
+// that values can be extracted using value_tag<T>
+// without specifying the value type.
+template<typename ValueType, typename Tag>
+struct feature_of<tag::value<ValueType, Tag> >
+  : feature_of<tag::value_tag<Tag> >
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/framework/depends_on.hpp b/boost/accumulators/framework/depends_on.hpp
new file mode 100644
index 0000000..76087b0
--- /dev/null
+++ b/boost/accumulators/framework/depends_on.hpp
@@ -0,0 +1,411 @@
+///////////////////////////////////////////////////////////////////////////////
+// depends_on.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_FRAMEWORK_DEPENDS_ON_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_FRAMEWORK_DEPENDS_ON_HPP_EAN_28_10_2005
+
+#include <boost/version.hpp>
+#include <boost/mpl/end.hpp>
+#include <boost/mpl/map.hpp>
+#include <boost/mpl/fold.hpp>
+#include <boost/mpl/size.hpp>
+#include <boost/mpl/sort.hpp>
+#include <boost/mpl/insert.hpp>
+#include <boost/mpl/assert.hpp>
+#include <boost/mpl/remove.hpp>
+#include <boost/mpl/vector.hpp>
+#include <boost/mpl/inherit.hpp>
+#include <boost/mpl/identity.hpp>
+#include <boost/mpl/equal_to.hpp>
+#include <boost/mpl/contains.hpp>
+#include <boost/mpl/transform.hpp>
+#include <boost/mpl/is_sequence.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/mpl/insert_range.hpp>
+#include <boost/mpl/transform_view.hpp>
+#include <boost/mpl/inherit_linearly.hpp>
+#include <boost/type_traits/is_base_and_derived.hpp>
+#include <boost/preprocessor/repetition/repeat.hpp>
+#include <boost/preprocessor/repetition/enum_params.hpp>
+#include <boost/preprocessor/facilities/intercept.hpp>
+#include <boost/accumulators/accumulators_fwd.hpp>
+#include <boost/fusion/include/next.hpp>
+#include <boost/fusion/include/equal_to.hpp>
+#include <boost/fusion/include/value_of.hpp>
+#include <boost/fusion/include/mpl.hpp>
+#include <boost/fusion/include/end.hpp>
+#include <boost/fusion/include/begin.hpp>
+#include <boost/fusion/include/cons.hpp>
+
+namespace boost { namespace accumulators
+{
+    ///////////////////////////////////////////////////////////////////////////
+    // as_feature
+    template<typename Feature>
+    struct as_feature
+    {
+        typedef Feature type;
+    };
+
+    ///////////////////////////////////////////////////////////////////////////
+    // weighted_feature
+    template<typename Feature>
+    struct as_weighted_feature
+    {
+        typedef Feature type;
+    };
+
+    ///////////////////////////////////////////////////////////////////////////
+    // feature_of
+    template<typename Feature>
+    struct feature_of
+    {
+        typedef Feature type;
+    };
+
+    namespace detail
+    {
+        ///////////////////////////////////////////////////////////////////////////
+        // feature_tag
+        template<typename Accumulator>
+        struct feature_tag
+        {
+            typedef typename Accumulator::feature_tag type;
+        };
+
+        template<typename Feature>
+        struct undroppable
+        {
+            typedef Feature type;
+        };
+
+        template<typename Feature>
+        struct undroppable<tag::droppable<Feature> >
+        {
+            typedef Feature type;
+        };
+
+        // For the purpose of determining whether one feature depends on another,
+        // disregard whether the feature is droppable or not.
+        template<typename A, typename B>
+        struct is_dependent_on
+          : is_base_and_derived<
+                typename undroppable<B>::type
+              , typename undroppable<A>::type
+            >
+        {};
+
+        template<typename Features>
+        struct depends_on_base
+          : mpl::inherit_linearly<
+                typename mpl::sort<Features, is_dependent_on<mpl::_1, mpl::_2> >::type
+                // Don't inherit multiply from a feature
+              , mpl::if_<
+                    is_dependent_on<mpl::_1, mpl::_2>
+                  , mpl::_1
+                  , mpl::inherit<mpl::_1, mpl::_2>
+                >
+            >::type
+        {
+        };
+    }
+
+    ///////////////////////////////////////////////////////////////////////////
+    /// depends_on
+    template<BOOST_PP_ENUM_PARAMS(BOOST_ACCUMULATORS_MAX_FEATURES, typename Feature)>
+    struct depends_on
+      : detail::depends_on_base<
+            typename mpl::transform<
+                mpl::vector<BOOST_PP_ENUM_PARAMS(BOOST_ACCUMULATORS_MAX_FEATURES, Feature)>
+              , as_feature<mpl::_1>
+            >::type
+        >
+    {
+        typedef mpl::false_ is_weight_accumulator;
+        typedef
+            typename mpl::transform<
+                mpl::vector<BOOST_PP_ENUM_PARAMS(BOOST_ACCUMULATORS_MAX_FEATURES, Feature)>
+              , as_feature<mpl::_1>
+            >::type
+        dependencies;
+    };
+
+    namespace detail
+    {
+        template<typename Feature>
+        struct matches_feature
+        {
+            template<typename Accumulator>
+            struct apply
+              : is_same<
+                    typename feature_of<typename as_feature<Feature>::type>::type
+                  , typename feature_of<typename as_feature<typename feature_tag<Accumulator>::type>::type>::type
+                >
+            {};
+        };
+
+        template<typename Features, typename Accumulator>
+        struct contains_feature_of
+        {
+            typedef
+                mpl::transform_view<Features, feature_of<as_feature<mpl::_> > >
+            features_list;
+
+            typedef
+                typename feature_of<typename feature_tag<Accumulator>::type>::type
+            the_feature;
+
+            typedef
+                typename mpl::contains<features_list, the_feature>::type
+            type;
+        };
+
+        // This is to work around a bug in early versions of Fusion which caused
+        // a compile error if contains_feature_of<List, mpl::_> is used as a
+        // predicate to fusion::find_if
+        template<typename Features>
+        struct contains_feature_of_
+        {
+            template<typename Accumulator>
+            struct apply
+              : contains_feature_of<Features, Accumulator>
+            {};
+        };
+
+        template<
+            typename First
+          , typename Last
+          , bool is_empty = fusion::result_of::equal_to<First, Last>::value
+        >
+        struct build_acc_list;
+
+        template<typename First, typename Last>
+        struct build_acc_list<First, Last, true>
+        {
+            typedef fusion::nil type;
+
+            template<typename Args>
+            static fusion::nil
+            call(Args const &, First const&, Last const&)
+            {
+                return fusion::nil();
+            }
+        };
+
+        template<typename First, typename Last>
+        struct build_acc_list<First, Last, false>
+        {
+            typedef
+                build_acc_list<typename fusion::result_of::next<First>::type, Last>
+            next_build_acc_list;
+
+            typedef fusion::cons<
+                typename fusion::result_of::value_of<First>::type
+              , typename next_build_acc_list::type>
+            type;
+
+            template<typename Args>
+            static type
+            call(Args const &args, First const& f, Last const& l)
+            {
+                return type(args, next_build_acc_list::call(args, fusion::next(f), l));
+            }
+        };
+
+        namespace meta
+        {
+            template<typename Sequence>
+            struct make_acc_list
+              : build_acc_list<
+                    typename fusion::result_of::begin<Sequence>::type
+                  , typename fusion::result_of::end<Sequence>::type
+                >
+            {};
+        }
+
+        template<typename Sequence, typename Args>
+        typename meta::make_acc_list<Sequence>::type
+        make_acc_list(Sequence const &seq, Args const &args)
+        {
+            return meta::make_acc_list<Sequence>::call(args, fusion::begin(seq), fusion::end(seq));
+        }
+
+        ///////////////////////////////////////////////////////////////////////////
+        // checked_as_weighted_feature
+        template<typename Feature>
+        struct checked_as_weighted_feature
+        {
+            typedef typename as_feature<Feature>::type feature_type;
+            typedef typename as_weighted_feature<feature_type>::type type;
+            // weighted and non-weighted flavors should provide the same feature.
+            BOOST_MPL_ASSERT((
+                is_same<
+                    typename feature_of<feature_type>::type
+                  , typename feature_of<type>::type
+                >
+            ));
+        };
+
+        ///////////////////////////////////////////////////////////////////////////
+        // as_feature_list
+        template<typename Features, typename Weight>
+        struct as_feature_list
+          : mpl::transform_view<Features, checked_as_weighted_feature<mpl::_1> >
+        {
+        };
+
+        template<typename Features>
+        struct as_feature_list<Features, void>
+          : mpl::transform_view<Features, as_feature<mpl::_1> >
+        {
+        };
+
+        ///////////////////////////////////////////////////////////////////////////
+        // accumulator_wrapper
+        template<typename Accumulator, typename Feature>
+        struct accumulator_wrapper
+          : Accumulator
+        {
+            typedef Feature feature_tag;
+
+            accumulator_wrapper(accumulator_wrapper const &that)
+              : Accumulator(*static_cast<Accumulator const *>(&that))
+            {
+            }
+
+            template<typename Args>
+            accumulator_wrapper(Args const &args)
+              : Accumulator(args)
+            {
+            }
+        };
+
+        ///////////////////////////////////////////////////////////////////////////
+        // to_accumulator
+        template<typename Feature, typename Sample, typename Weight>
+        struct to_accumulator
+        {
+            typedef
+                accumulator_wrapper<
+                    typename mpl::apply2<typename Feature::impl, Sample, Weight>::type
+                  , Feature
+                >
+            type;
+        };
+
+        template<typename Feature, typename Sample, typename Weight, typename Tag, typename AccumulatorSet>
+        struct to_accumulator<Feature, Sample, tag::external<Weight, Tag, AccumulatorSet> >
+        {
+            BOOST_MPL_ASSERT((is_same<Tag, void>));
+            BOOST_MPL_ASSERT((is_same<AccumulatorSet, void>));
+
+            typedef
+                accumulator_wrapper<
+                    typename mpl::apply2<typename Feature::impl, Sample, Weight>::type
+                  , Feature
+                >
+            accumulator_type;
+
+            typedef
+                typename mpl::if_<
+                    typename Feature::is_weight_accumulator
+                  , accumulator_wrapper<impl::external_impl<accumulator_type, tag::weights>, Feature>
+                  , accumulator_type
+                >::type
+            type;
+        };
+
+        // BUGBUG work around a MPL bug wrt map insertion
+        template<typename FeatureMap, typename Feature>
+        struct insert_feature
+          : mpl::eval_if<
+                mpl::has_key<FeatureMap, typename feature_of<Feature>::type>
+              , mpl::identity<FeatureMap>
+              , mpl::insert<FeatureMap, mpl::pair<typename feature_of<Feature>::type, Feature> >
+            >
+        {
+        };
+
+        template<typename FeatureMap, typename Feature, typename Weight>
+        struct insert_dependencies
+          : mpl::fold<
+                as_feature_list<typename Feature::dependencies, Weight>
+              , FeatureMap
+              , insert_dependencies<
+                    insert_feature<mpl::_1, mpl::_2>
+                  , mpl::_2
+                  , Weight
+                >
+            >
+        {
+        };
+
+        template<typename FeatureMap, typename Features, typename Weight>
+        struct insert_sequence
+          : mpl::fold< // BUGBUG should use insert_range, but doesn't seem to work for maps
+                as_feature_list<Features, Weight>
+              , FeatureMap
+              , insert_feature<mpl::_1, mpl::_2>
+            >
+        {
+        };
+
+        template<typename Features, typename Sample, typename Weight>
+        struct make_accumulator_tuple
+        {
+            typedef
+                typename mpl::fold<
+                    as_feature_list<Features, Weight>
+                  , mpl::map0<>
+                  , mpl::if_<
+                        mpl::is_sequence<mpl::_2>
+                      , insert_sequence<mpl::_1, mpl::_2, Weight>
+                      , insert_feature<mpl::_1, mpl::_2>
+                    >
+                >::type
+            feature_map;
+
+            // for each element in the map, add its dependencies also
+            typedef
+                typename mpl::fold<
+                    feature_map
+                  , feature_map
+                  , insert_dependencies<mpl::_1, mpl::second<mpl::_2>, Weight>
+                >::type
+            feature_map_with_dependencies;
+
+            // turn the map into a vector so we can sort it
+            typedef
+                typename mpl::insert_range<
+                    mpl::vector<>
+                  , mpl::end<mpl::vector<> >::type
+                  , mpl::transform_view<feature_map_with_dependencies, mpl::second<mpl::_1> >
+                >::type
+            feature_vector_with_dependencies;
+
+            // sort the features according to which is derived from which
+            typedef
+                typename mpl::sort<
+                    feature_vector_with_dependencies
+                  , is_dependent_on<mpl::_2, mpl::_1>
+                >::type
+            sorted_feature_vector;
+
+            // From the vector of features, construct a vector of accumulators
+            typedef
+                typename mpl::transform<
+                    sorted_feature_vector
+                  , to_accumulator<mpl::_1, Sample, Weight>
+                >::type
+            type;
+        };
+
+    } // namespace detail
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/framework/external.hpp b/boost/accumulators/framework/external.hpp
new file mode 100644
index 0000000..dbd5d91
--- /dev/null
+++ b/boost/accumulators/framework/external.hpp
@@ -0,0 +1,27 @@
+///////////////////////////////////////////////////////////////////////////////
+// external.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_FRAMEWORK_EXTERNAL_HPP_EAN_01_12_2005
+#define BOOST_ACCUMULATORS_FRAMEWORK_EXTERNAL_HPP_EAN_01_12_2005
+
+#include <boost/mpl/apply.hpp>
+#include <boost/accumulators/framework/accumulators/external_accumulator.hpp>
+
+//namespace boost { namespace accumulators
+//{
+//
+/////////////////////////////////////////////////////////////////////////////////
+//// external
+////
+//template<typename Type>
+//struct external
+//{
+//};
+//
+//}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/framework/extractor.hpp b/boost/accumulators/framework/extractor.hpp
new file mode 100644
index 0000000..98281ce
--- /dev/null
+++ b/boost/accumulators/framework/extractor.hpp
@@ -0,0 +1,229 @@
+///////////////////////////////////////////////////////////////////////////////
+// extractor.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_FRAMEWORK_EXTRACTOR_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_FRAMEWORK_EXTRACTOR_HPP_EAN_28_10_2005
+
+#include <boost/preprocessor/tuple/rem.hpp>
+#include <boost/preprocessor/array/size.hpp>
+#include <boost/preprocessor/array/data.hpp>
+#include <boost/preprocessor/array/elem.hpp>
+#include <boost/preprocessor/seq/to_array.hpp>
+#include <boost/preprocessor/seq/transform.hpp>
+#include <boost/preprocessor/repetition/enum_params.hpp>
+#include <boost/preprocessor/repetition/enum_trailing_params.hpp>
+#include <boost/preprocessor/repetition/enum_trailing_binary_params.hpp>
+#include <boost/parameter/binding.hpp>
+#include <boost/mpl/apply.hpp>
+#include <boost/mpl/eval_if.hpp>
+#include <boost/type_traits/remove_reference.hpp>
+#include <boost/accumulators/accumulators_fwd.hpp>
+#include <boost/accumulators/framework/parameters/accumulator.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace detail
+{
+    template<typename AccumulatorSet, typename Feature>
+    struct accumulator_set_result
+    {
+        typedef typename as_feature<Feature>::type feature_type;
+        typedef typename mpl::apply<AccumulatorSet, feature_type>::type::result_type type;
+    };
+
+    template<typename Args, typename Feature>
+    struct argument_pack_result
+      : accumulator_set_result<
+            typename remove_reference<
+                typename parameter::binding<Args, tag::accumulator>::type
+            >::type
+          , Feature
+        >
+    {
+    };
+
+    template<typename A, typename Feature>
+    struct extractor_result
+      : mpl::eval_if<
+            detail::is_accumulator_set<A>
+          , accumulator_set_result<A, Feature>
+          , argument_pack_result<A, Feature>
+        >
+    {
+    };
+
+    template<typename Feature, typename AccumulatorSet>
+    typename extractor_result<AccumulatorSet, Feature>::type
+    do_extract(AccumulatorSet const &acc, mpl::true_)
+    {
+        typedef typename as_feature<Feature>::type feature_type;
+        return extract_result<feature_type>(acc);
+    }
+
+    template<typename Feature, typename Args>
+    typename extractor_result<Args, Feature>::type
+    do_extract(Args const &args, mpl::false_)
+    {
+        typedef typename as_feature<Feature>::type feature_type;
+        return find_accumulator<feature_type>(args[accumulator]).result(args);
+    }
+
+} // namespace detail
+
+
+///////////////////////////////////////////////////////////////////////////////
+/// Extracts the result associated with Feature from the specified accumulator_set.
+template<typename Feature>
+struct extractor
+{
+    typedef extractor<Feature> this_type;
+
+    /// The result meta-function for determining the return type of the extractor
+    template<typename F>
+    struct result;
+
+    template<typename A1>
+    struct result<this_type(A1)>
+      : detail::extractor_result<A1, Feature>
+    {
+    };
+
+    /// Extract the result associated with Feature from the accumulator set
+    /// \param acc The accumulator set object from which to extract the result
+    template<typename Arg1>
+    typename detail::extractor_result<Arg1, Feature>::type
+    operator ()(Arg1 const &arg1) const
+    {
+        // Arg1 could be an accumulator_set or an argument pack containing
+        // an accumulator_set. Dispatch accordingly.
+        return detail::do_extract<Feature>(arg1, detail::is_accumulator_set<Arg1>());
+    }
+
+    /// \overload
+    ///
+    /// \param a1 Optional named parameter to be passed to the accumulator's result() function.
+    template<typename AccumulatorSet, typename A1>
+    typename detail::extractor_result<AccumulatorSet, Feature>::type
+    operator ()(AccumulatorSet const &acc, A1 const &a1) const
+    {
+        BOOST_MPL_ASSERT((detail::is_accumulator_set<AccumulatorSet>));
+        typedef typename as_feature<Feature>::type feature_type;
+        return extract_result<feature_type>(acc, a1);
+    }
+
+    // ... other overloads generated by Boost.Preprocessor:
+
+    /// INTERNAL ONLY
+    ///
+#define BOOST_ACCUMULATORS_EXTRACTOR_FUN_OP(z, n, _)                                    \
+    template<BOOST_PP_ENUM_PARAMS_Z(z, n, typename A)>                                  \
+    struct result<this_type(BOOST_PP_ENUM_PARAMS_Z(z, n, A))>                           \
+      : detail::extractor_result<A1, Feature>                                           \
+    {};                                                                                 \
+    template<                                                                           \
+        typename AccumulatorSet                                                         \
+        BOOST_PP_ENUM_TRAILING_PARAMS_Z(z, n, typename A)                               \
+    >                                                                                   \
+    typename detail::extractor_result<AccumulatorSet, Feature>::type                    \
+    operator ()(                                                                        \
+        AccumulatorSet const &acc                                                       \
+        BOOST_PP_ENUM_TRAILING_BINARY_PARAMS_Z(z, n, A, const &a)                       \
+    ) const                                                                             \
+    {                                                                                   \
+        BOOST_MPL_ASSERT((detail::is_accumulator_set<AccumulatorSet>));                 \
+        typedef typename as_feature<Feature>::type feature_type;                        \
+        return extract_result<feature_type>(acc BOOST_PP_ENUM_TRAILING_PARAMS_Z(z, n, a));\
+    }
+
+    BOOST_PP_REPEAT_FROM_TO(
+        2
+      , BOOST_PP_INC(BOOST_ACCUMULATORS_MAX_ARGS)
+      , BOOST_ACCUMULATORS_EXTRACTOR_FUN_OP
+      , _
+    )
+
+    #ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
+    /// \overload
+    ///
+    template<typename AccumulatorSet, typename A1, typename A2, ...>
+    typename detail::extractor_result<AccumulatorSet, Feature>::type
+    operator ()(AccumulatorSet const &acc, A1 const &a1, A2 const &a2, ...);
+    #endif
+};
+
+/// INTERNAL ONLY
+///
+#define BOOST_ACCUMULATORS_ARRAY_REM(Array)                                                         \
+    BOOST_PP_TUPLE_REM_CTOR(BOOST_PP_ARRAY_SIZE(Array), BOOST_PP_ARRAY_DATA(Array))
+
+/// INTERNAL ONLY
+///
+#define BOOST_ACCUMULATORS_SEQ_REM(Seq)                                                             \
+    BOOST_ACCUMULATORS_ARRAY_REM(BOOST_PP_SEQ_TO_ARRAY(Seq))
+
+/// INTERNAL ONLY
+///
+#define BOOST_ACCUMULATORS_ARGS_OP(s, data, elem)                                                   \
+    T ## s
+
+/// INTERNAL ONLY
+///
+#define BOOST_ACCUMULATORS_PARAMS_OP(s, data, elem)                                                 \
+    elem T ## s
+
+/// INTERNAL ONLY
+///
+#define BOOST_ACCUMULATORS_MAKE_FEATURE(Tag, Feature, ParamsSeq)                                    \
+    Tag::Feature<                                                                                   \
+        BOOST_ACCUMULATORS_SEQ_REM(                                                                 \
+            BOOST_PP_SEQ_TRANSFORM(BOOST_ACCUMULATORS_ARGS_OP, ~, ParamsSeq)                        \
+        )                                                                                           \
+    >
+
+/// INTERNAL ONLY
+///
+#define BOOST_ACCUMULATORS_DEFINE_EXTRACTOR_FUN_IMPL(z, n, Tag, Feature, ParamsSeq)                 \
+    template<                                                                                       \
+        BOOST_ACCUMULATORS_SEQ_REM(                                                                 \
+            BOOST_PP_SEQ_TRANSFORM(BOOST_ACCUMULATORS_PARAMS_OP, ~, ParamsSeq)                      \
+        )                                                                                           \
+      , typename Arg1                                                                               \
+        BOOST_PP_ENUM_TRAILING_PARAMS_Z(z, n, typename A)                                           \
+    >                                                                                               \
+    typename boost::accumulators::detail::extractor_result<                                         \
+        Arg1                                                                                        \
+      , BOOST_ACCUMULATORS_MAKE_FEATURE(Tag, Feature, ParamsSeq)                                    \
+    >::type                                                                                         \
+    Feature(Arg1 const &arg1 BOOST_PP_ENUM_TRAILING_BINARY_PARAMS_Z(z, n, A, const &a) )            \
+    {                                                                                               \
+        typedef BOOST_ACCUMULATORS_MAKE_FEATURE(Tag, Feature, ParamsSeq) feature_type;              \
+        return boost::accumulators::extractor<feature_type>()(                                      \
+            arg1 BOOST_PP_ENUM_TRAILING_PARAMS_Z(z, n, a));                                         \
+    }
+
+/// INTERNAL ONLY
+///
+#define BOOST_ACCUMULATORS_DEFINE_EXTRACTOR_FUN(z, n, _)                                            \
+    BOOST_ACCUMULATORS_DEFINE_EXTRACTOR_FUN_IMPL(                                                   \
+        z                                                                                           \
+      , n                                                                                           \
+      , BOOST_PP_ARRAY_ELEM(0, _)                                                                   \
+      , BOOST_PP_ARRAY_ELEM(1, _)                                                                   \
+      , BOOST_PP_ARRAY_ELEM(2, _)                                                                   \
+    )
+
+#define BOOST_ACCUMULATORS_DEFINE_EXTRACTOR(Tag, Feature, ParamSeq)                                 \
+    BOOST_PP_REPEAT(                                                                                \
+        BOOST_PP_INC(BOOST_ACCUMULATORS_MAX_ARGS)                                                   \
+      , BOOST_ACCUMULATORS_DEFINE_EXTRACTOR_FUN                                                     \
+      , (3, (Tag, Feature, ParamSeq))                                                               \
+    )
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/framework/features.hpp b/boost/accumulators/framework/features.hpp
new file mode 100644
index 0000000..21cae00
--- /dev/null
+++ b/boost/accumulators/framework/features.hpp
@@ -0,0 +1,29 @@
+///////////////////////////////////////////////////////////////////////////////
+// features.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_STATS_HPP_EAN_08_12_2005
+#define BOOST_ACCUMULATORS_STATISTICS_STATS_HPP_EAN_08_12_2005
+
+#include <boost/preprocessor/repetition/enum_params.hpp>
+#include <boost/mpl/vector.hpp>
+#include <boost/accumulators/accumulators_fwd.hpp>
+
+namespace boost { namespace accumulators
+{
+
+///////////////////////////////////////////////////////////////////////////////
+// features
+//
+template<BOOST_PP_ENUM_PARAMS(BOOST_ACCUMULATORS_MAX_FEATURES, typename Feature)>
+struct features
+  : mpl::vector<BOOST_PP_ENUM_PARAMS(BOOST_ACCUMULATORS_MAX_FEATURES, Feature)>
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/framework/parameters/accumulator.hpp b/boost/accumulators/framework/parameters/accumulator.hpp
new file mode 100644
index 0000000..30e4b0d
--- /dev/null
+++ b/boost/accumulators/framework/parameters/accumulator.hpp
@@ -0,0 +1,20 @@
+///////////////////////////////////////////////////////////////////////////////
+// accumulator.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_FRAMEWORK_PARAMETERS_ACCUMULATOR_HPP_EAN_31_10_2005
+#define BOOST_ACCUMULATORS_FRAMEWORK_PARAMETERS_ACCUMULATOR_HPP_EAN_31_10_2005
+
+#include <boost/parameter/keyword.hpp>
+
+namespace boost { namespace accumulators
+{
+
+BOOST_PARAMETER_KEYWORD(tag, accumulator)
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/framework/parameters/sample.hpp b/boost/accumulators/framework/parameters/sample.hpp
new file mode 100644
index 0000000..9bfb665
--- /dev/null
+++ b/boost/accumulators/framework/parameters/sample.hpp
@@ -0,0 +1,20 @@
+///////////////////////////////////////////////////////////////////////////////
+// sample.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_FRAMEWORK_PARAMETERS_SAMPLE_HPP_EAN_31_10_2005
+#define BOOST_ACCUMULATORS_FRAMEWORK_PARAMETERS_SAMPLE_HPP_EAN_31_10_2005
+
+#include <boost/parameter/keyword.hpp>
+
+namespace boost { namespace accumulators
+{
+
+BOOST_PARAMETER_KEYWORD(tag, sample)
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/framework/parameters/weight.hpp b/boost/accumulators/framework/parameters/weight.hpp
new file mode 100644
index 0000000..86f133b
--- /dev/null
+++ b/boost/accumulators/framework/parameters/weight.hpp
@@ -0,0 +1,21 @@
+///////////////////////////////////////////////////////////////////////////////
+// weight.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_FRAMEWORK_PARAMETERS_WEIGHT_HPP_EAN_31_10_2005
+#define BOOST_ACCUMULATORS_FRAMEWORK_PARAMETERS_WEIGHT_HPP_EAN_31_10_2005
+
+#include <boost/parameter/keyword.hpp>
+
+namespace boost { namespace accumulators
+{
+
+// The weight of a single sample
+BOOST_PARAMETER_KEYWORD(tag, weight)
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/framework/parameters/weights.hpp b/boost/accumulators/framework/parameters/weights.hpp
new file mode 100644
index 0000000..85b9e2f
--- /dev/null
+++ b/boost/accumulators/framework/parameters/weights.hpp
@@ -0,0 +1,21 @@
+///////////////////////////////////////////////////////////////////////////////
+// weights.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_FRAMEWORK_PARAMETERS_WEIGHTS_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_FRAMEWORK_PARAMETERS_WEIGHTS_HPP_EAN_28_10_2005
+
+#include <boost/parameter/keyword.hpp>
+
+namespace boost { namespace accumulators
+{
+
+// The weight accumulator
+BOOST_PARAMETER_KEYWORD(tag, weights)
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/numeric/detail/function1.hpp b/boost/accumulators/numeric/detail/function1.hpp
new file mode 100644
index 0000000..282eb1e
--- /dev/null
+++ b/boost/accumulators/numeric/detail/function1.hpp
@@ -0,0 +1,75 @@
+// Copyright David Abrahams 2006. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+#ifndef BOOST_DETAIL_FUNCTION1_DWA200655_HPP
+# define BOOST_DETAIL_FUNCTION1_DWA200655_HPP
+
+# include <boost/concept_check.hpp>
+# include <boost/type_traits/remove_reference.hpp>
+# include <boost/type_traits/add_const.hpp>
+# include <boost/mpl/apply.hpp>
+
+namespace boost { namespace detail {
+
+// A utility for creating unary function objects that play nicely with
+// boost::result_of and that handle the forwarding problem.
+//
+// mpl::apply<F, A0>::type is expected to be a stateless function
+// object that accepts an argument of type A0&.  It is also expected
+// to have a nested ::result_type identical to its return type.
+template<typename F>
+struct function1
+{
+    template<typename Signature>
+    struct result
+    {};
+
+    template<typename This, typename A0>
+    struct result<This(A0)>
+    {
+        // How adding const to arguments handles rvalues.
+        //
+        // if A0 is     arg0 is       represents actual argument
+        // --------     -------       --------------------------
+        // T const &    T const       const T lvalue
+        // T &          T             non-const T lvalue
+        // T const      T const       const T rvalue
+        // T            T const       non-const T rvalue
+        typedef typename remove_reference<
+            typename add_const< A0 >::type
+        >::type arg0;
+
+        typedef typename mpl::apply1<F, arg0>::type impl;
+        typedef typename impl::result_type type;
+    };
+
+    // Handles mutable lvalues
+    template<typename A0>
+    typename result<function1(A0 &)>::type
+    operator ()(A0 &a0) const
+    {
+        typedef typename result<function1(A0 &)>::impl impl;
+        typedef typename result<function1(A0 &)>::type type;
+        typedef A0 &arg0;
+        BOOST_CONCEPT_ASSERT((UnaryFunction<impl, type, arg0>));
+        //boost::function_requires<UnaryFunctionConcept<impl, type, arg0> >();
+        return impl()(a0);
+    }
+
+    // Handles const lvalues and all rvalues
+    template<typename A0>
+    typename result<function1(A0 const &)>::type
+    operator ()(A0 const &a0) const
+    {
+        typedef typename result<function1(A0 const &)>::impl impl;
+        typedef typename result<function1(A0 const &)>::type type;
+        typedef A0 const &arg0;
+        BOOST_CONCEPT_ASSERT((UnaryFunction<impl, type, arg0>));
+        //boost::function_requires<UnaryFunctionConcept<impl, type, arg0> >();
+        return impl()(a0);
+    }
+};
+
+}} // namespace boost::detail
+
+#endif // BOOST_DETAIL_FUNCTION1_DWA200655_HPP
diff --git a/boost/accumulators/numeric/detail/function2.hpp b/boost/accumulators/numeric/detail/function2.hpp
new file mode 100644
index 0000000..daf3c4d
--- /dev/null
+++ b/boost/accumulators/numeric/detail/function2.hpp
@@ -0,0 +1,10 @@
+// Copyright David Abrahams 2006. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+#ifndef BOOST_DETAIL_FUNCTION2_DWA200655_HPP
+# define BOOST_DETAIL_FUNCTION2_DWA200655_HPP
+
+# define args (2)
+# include <boost/accumulators/numeric/detail/function_n.hpp>
+
+#endif // BOOST_DETAIL_FUNCTION2_DWA200655_HPP
diff --git a/boost/accumulators/numeric/detail/function3.hpp b/boost/accumulators/numeric/detail/function3.hpp
new file mode 100644
index 0000000..175e4d5
--- /dev/null
+++ b/boost/accumulators/numeric/detail/function3.hpp
@@ -0,0 +1,10 @@
+// Copyright David Abrahams 2006. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+#ifndef BOOST_DETAIL_FUNCTION3_DWA2006514_HPP
+# define BOOST_DETAIL_FUNCTION3_DWA2006514_HPP
+
+# define args (3)
+# include <boost/accumulators/numeric/detail/function_n.hpp>
+
+#endif // BOOST_DETAIL_FUNCTION3_DWA2006514_HPP
diff --git a/boost/accumulators/numeric/detail/function4.hpp b/boost/accumulators/numeric/detail/function4.hpp
new file mode 100644
index 0000000..a0d7108
--- /dev/null
+++ b/boost/accumulators/numeric/detail/function4.hpp
@@ -0,0 +1,10 @@
+// Copyright David Abrahams 2006. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+#ifndef BOOST_DETAIL_FUNCTION4_DWA2006514_HPP
+# define BOOST_DETAIL_FUNCTION4_DWA2006514_HPP
+
+# define args (4)
+# include <boost/accumulators/numeric/detail/function_n.hpp>
+
+#endif // BOOST_DETAIL_FUNCTION4_DWA2006514_HPP
diff --git a/boost/accumulators/numeric/detail/function_n.hpp b/boost/accumulators/numeric/detail/function_n.hpp
new file mode 100644
index 0000000..47c42ed
--- /dev/null
+++ b/boost/accumulators/numeric/detail/function_n.hpp
@@ -0,0 +1,148 @@
+// Copyright David Abrahams 2006. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// #include guards intentionally disabled.
+// #ifndef BOOST_DETAIL_FUNCTION_N_DWA2006514_HPP
+// # define BOOST_DETAIL_FUNCTION_N_DWA2006514_HPP
+
+#include <boost/mpl/void.hpp>
+#include <boost/mpl/apply.hpp>
+
+#include <boost/preprocessor/control/if.hpp>
+#include <boost/preprocessor/cat.hpp>
+#include <boost/preprocessor/punctuation/comma_if.hpp>
+#include <boost/preprocessor/repetition/enum_params.hpp>
+#include <boost/preprocessor/repetition/enum_trailing_params.hpp>
+#include <boost/preprocessor/repetition/repeat.hpp>
+#include <boost/preprocessor/seq/fold_left.hpp>
+#include <boost/preprocessor/seq/seq.hpp>
+#include <boost/preprocessor/seq/for_each.hpp>
+#include <boost/preprocessor/seq/for_each_i.hpp>
+#include <boost/preprocessor/seq/for_each_product.hpp>
+#include <boost/preprocessor/seq/size.hpp>
+#include <boost/type_traits/add_const.hpp>
+#include <boost/type_traits/remove_reference.hpp>
+
+namespace boost { namespace detail {
+
+# define BOOST_DETAIL_default_arg(z, n, _)                                      \
+    typedef mpl::void_ BOOST_PP_CAT(arg, n);
+
+# define BOOST_DETAIL_function_arg(z, n, _)                                     \
+    typedef typename remove_reference<                                          \
+        typename add_const< BOOST_PP_CAT(A, n) >::type                          \
+    >::type BOOST_PP_CAT(arg, n);
+
+#define BOOST_DETAIL_cat_arg_counts(s, state, n)                                \
+    BOOST_PP_IF(                                                                \
+        n                                                                       \
+      , BOOST_PP_CAT(state, BOOST_PP_CAT(_, n))                                 \
+      , state                                                                   \
+    )                                                                           \
+    /**/
+
+#define function_name                                                           \
+    BOOST_PP_SEQ_FOLD_LEFT(                                                     \
+        BOOST_DETAIL_cat_arg_counts                                             \
+      , BOOST_PP_CAT(function, BOOST_PP_SEQ_HEAD(args))                         \
+      , BOOST_PP_SEQ_TAIL(args)(0)                                              \
+    )                                                                           \
+    /**/
+
+template<typename F>
+struct function_name
+{
+    BOOST_PP_REPEAT(
+        BOOST_MPL_LIMIT_METAFUNCTION_ARITY
+      , BOOST_DETAIL_default_arg
+      , ~
+    )
+
+    template<typename Signature>
+    struct result {};
+
+#define BOOST_DETAIL_function_result(r, _, n)                                   \
+    template<typename This BOOST_PP_ENUM_TRAILING_PARAMS(n, typename A)>        \
+    struct result<This(BOOST_PP_ENUM_PARAMS(n, A))>                             \
+    {                                                                           \
+        BOOST_PP_REPEAT(n, BOOST_DETAIL_function_arg, ~)                        \
+        typedef                                                                 \
+            typename BOOST_PP_CAT(mpl::apply, BOOST_MPL_LIMIT_METAFUNCTION_ARITY)<\
+                F                                                               \
+                BOOST_PP_ENUM_TRAILING_PARAMS(                                  \
+                    BOOST_MPL_LIMIT_METAFUNCTION_ARITY                          \
+                  , arg                                                         \
+                )                                                               \
+            >::type                                                             \
+        impl;                                                                   \
+        typedef typename impl::result_type type;                                \
+    };                                                                          \
+    /**/
+
+    BOOST_PP_SEQ_FOR_EACH(BOOST_DETAIL_function_result, _, args)
+
+# define arg_type(r, _, i, is_const)                                            \
+    BOOST_PP_COMMA_IF(i) BOOST_PP_CAT(A, i) BOOST_PP_CAT(const_if, is_const) &
+
+# define result_(r, n, constness)                                               \
+    typename result<                                                            \
+        function_name(                                                          \
+            BOOST_PP_SEQ_FOR_EACH_I_R(r, arg_type, ~, constness)                \
+        )                                                                       \
+    >                                                                           \
+    /**/
+
+# define param(r, _, i, is_const) BOOST_PP_COMMA_IF(i)                          \
+    BOOST_PP_CAT(A, i) BOOST_PP_CAT(const_if, is_const) & BOOST_PP_CAT(x, i)
+
+# define param_list(r, n, constness)                                            \
+    BOOST_PP_SEQ_FOR_EACH_I_R(r, param, ~, constness)
+
+# define call_operator(r, constness)                                            \
+    template<BOOST_PP_ENUM_PARAMS(BOOST_PP_SEQ_SIZE(constness), typename A)>    \
+        result_(r, BOOST_PP_SEQ_SIZE(constness), constness)::type               \
+    operator ()( param_list(r, BOOST_PP_SEQ_SIZE(constness), constness) ) const \
+    {                                                                           \
+        typedef result_(r, BOOST_PP_SEQ_SIZE(constness), constness)::impl impl; \
+        return impl()(BOOST_PP_ENUM_PARAMS(BOOST_PP_SEQ_SIZE(constness), x));   \
+    }                                                                           \
+    /**/
+
+# define const_if0
+# define const_if1 const
+
+# define bits(z, n, _) ((0)(1))
+
+# define gen_operator(r, _, n)                                                  \
+    BOOST_PP_SEQ_FOR_EACH_PRODUCT_R(                                            \
+        r                                                                       \
+      , call_operator                                                           \
+      , BOOST_PP_REPEAT(n, bits, ~)                                             \
+    )                                                                           \
+    /**/
+
+    BOOST_PP_SEQ_FOR_EACH(
+        gen_operator
+      , ~
+      , args
+    )
+
+# undef bits
+# undef const_if1
+# undef const_if0
+# undef call_operator
+# undef param_list
+# undef param
+# undef result_
+# undef default_
+# undef arg_type
+# undef gen_operator
+# undef function_name
+
+# undef args
+};
+
+}} // namespace boost::detail
+
+//#endif // BOOST_DETAIL_FUNCTION_N_DWA2006514_HPP
diff --git a/boost/accumulators/numeric/detail/pod_singleton.hpp b/boost/accumulators/numeric/detail/pod_singleton.hpp
new file mode 100644
index 0000000..317d85f
--- /dev/null
+++ b/boost/accumulators/numeric/detail/pod_singleton.hpp
@@ -0,0 +1,20 @@
+// Copyright David Abrahams 2006. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+#ifndef BOOST_DETAIL_POD_SINGLETON_DWA200655_HPP
+# define BOOST_DETAIL_POD_SINGLETON_DWA200655_HPP
+
+namespace boost { namespace detail {
+
+template<typename T>
+struct pod_singleton
+{
+    static T instance;
+};
+
+template<typename T>
+T pod_singleton<T>::instance;
+
+}} // namespace boost::detail
+
+#endif // BOOST_DETAIL_POD_SINGLETON_DWA200655_HPP
diff --git a/boost/accumulators/numeric/functional.hpp b/boost/accumulators/numeric/functional.hpp
new file mode 100644
index 0000000..9d955db
--- /dev/null
+++ b/boost/accumulators/numeric/functional.hpp
@@ -0,0 +1,490 @@
+///////////////////////////////////////////////////////////////////////////////
+/// \file functional.hpp
+///
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_NUMERIC_FUNCTIONAL_HPP_EAN_08_12_2005
+#define BOOST_NUMERIC_FUNCTIONAL_HPP_EAN_08_12_2005
+
+#include <limits>
+#include <functional>
+#include <boost/mpl/if.hpp>
+#include <boost/mpl/and.hpp>
+#include <boost/type_traits/remove_const.hpp>
+#include <boost/type_traits/add_reference.hpp>
+#include <boost/type_traits/is_empty.hpp>
+#include <boost/type_traits/is_integral.hpp>
+#include <boost/type_traits/is_floating_point.hpp>
+#include <boost/utility/enable_if.hpp>
+#include <boost/typeof/typeof.hpp>
+#include <boost/accumulators/numeric/functional_fwd.hpp>
+#include <boost/accumulators/numeric/detail/function1.hpp>
+#include <boost/accumulators/numeric/detail/function2.hpp>
+#include <boost/accumulators/numeric/detail/pod_singleton.hpp>
+
+#ifdef BOOST_NUMERIC_FUNCTIONAL_STD_VECTOR_SUPPORT
+# include <boost/accumulators/numeric/functional/vector.hpp>
+#endif
+
+#ifdef BOOST_NUMERIC_FUNCTIONAL_STD_VALARRAY_SUPPORT
+# include <boost/accumulators/numeric/functional/valarray.hpp>
+#endif
+
+#ifdef BOOST_NUMERIC_FUNCTIONAL_STD_COMPLEX_SUPPORT
+# include <boost/accumulators/numeric/functional/complex.hpp>
+#endif
+
+/// INTERNAL ONLY
+///
+#define BOOST_NUMERIC_FUNCTIONAL_HPP_INCLUDED
+
+#ifdef BOOST_NUMERIC_FUNCTIONAL_DOXYGEN_INVOKED
+// Hack to make Doxygen show the inheritance relationships
+/// INTERNAL ONLY
+///
+namespace std
+{
+    /// INTERNAL ONLY
+    ///
+    template<class Arg, class Ret> struct unary_function {};
+    /// INTERNAL ONLY
+    ///
+    template<class Left, class Right, class Ret> struct binary_function {};
+}
+#endif
+
+namespace boost { namespace numeric
+{
+    namespace functional
+    {
+        /// INTERNAL ONLY
+        ///
+        template<typename A0, typename A1>
+        struct are_integral
+          : mpl::and_<is_integral<A0>, is_integral<A1> >
+        {};
+
+        template<typename Left, typename Right>
+        struct left_ref
+        {
+            typedef Left &type;
+        };
+
+        namespace detail
+        {
+            template<typename T>
+            T &lvalue_of();
+        }
+    }
+
+    // TODO: handle complex weight, valarray, MTL vectors
+
+    /// INTERNAL ONLY
+    ///
+#define BOOST_NUMERIC_FUNCTIONAL_DEFINE_UNARY_OP(Name, Op)                                      \
+    namespace functional                                                                        \
+    {                                                                                           \
+        template<typename Arg>                                                                  \
+        struct result_of_ ## Name                                                               \
+        {                                                                                       \
+            BOOST_TYPEOF_NESTED_TYPEDEF_TPL(                                                    \
+                nested                                                                          \
+              , Op boost::numeric::functional::detail::lvalue_of<Arg>()                         \
+            )                                                                                   \
+            typedef typename nested::type type;                                                 \
+        };                                                                                      \
+        template<typename Arg, typename EnableIf>                                               \
+        struct Name ## _base                                                                    \
+          : std::unary_function<                                                                \
+                typename remove_const<Arg>::type                                                \
+              , typename result_of_ ## Name<Arg>::type                                          \
+            >                                                                                   \
+        {                                                                                       \
+            typename result_of_ ## Name<Arg>::type operator ()(Arg &arg) const                  \
+            {                                                                                   \
+                return Op arg;                                                                  \
+            }                                                                                   \
+        };                                                                                      \
+        template<typename Arg, typename ArgTag>                                                 \
+        struct Name                                                                             \
+          : Name ## _base<Arg, void>                                                            \
+        {};                                                                                     \
+    }                                                                                           \
+    namespace op                                                                                \
+    {                                                                                           \
+        struct Name                                                                             \
+          : boost::detail::function1<functional::Name<_, functional::tag<_> > >                 \
+        {};                                                                                     \
+    }                                                                                           \
+    namespace                                                                                   \
+    {                                                                                           \
+        op::Name const &Name = boost::detail::pod_singleton<op::Name>::instance;                \
+    }                                                                                           \
+    /**/
+
+    /// INTERNAL ONLY
+    ///
+#define BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(Name, Op, RetType)                            \
+    namespace functional                                                                        \
+    {                                                                                           \
+        template<typename Left, typename Right, typename EnableIf>                              \
+        struct result_of_ ## Name                                                               \
+        {                                                                                       \
+            RetType(Left, Op, Right)                                                            \
+        };                                                                                      \
+        template<typename Left, typename Right, typename EnableIf>                              \
+        struct Name ## _base                                                                    \
+          : std::binary_function<                                                               \
+                typename remove_const<Left>::type                                               \
+              , typename remove_const<Right>::type                                              \
+              , typename result_of_ ## Name<Left, Right>::type                                  \
+            >                                                                                   \
+        {                                                                                       \
+            typename result_of_ ## Name<Left, Right>::type                                      \
+            operator ()(Left &left, Right &right) const                                         \
+            {                                                                                   \
+                return left Op right;                                                           \
+            }                                                                                   \
+        };                                                                                      \
+        template<typename Left, typename Right, typename LeftTag, typename RightTag>            \
+        struct Name                                                                             \
+          : Name ## _base<Left, Right, void>                                                    \
+        {};                                                                                     \
+    }                                                                                           \
+    namespace op                                                                                \
+    {                                                                                           \
+        struct Name                                                                             \
+          : boost::detail::function2<                                                           \
+                functional::Name<_1, _2, functional::tag<_1>, functional::tag<_2> >             \
+            >                                                                                   \
+        {};                                                                                     \
+    }                                                                                           \
+    namespace                                                                                   \
+    {                                                                                           \
+        op::Name const &Name = boost::detail::pod_singleton<op::Name>::instance;                \
+    }                                                                                           \
+    /**/
+
+    /// INTERNAL ONLY
+    ///
+#define BOOST_NUMERIC_FUNCTIONAL_DEDUCED(Left, Op, Right)                                       \
+    BOOST_TYPEOF_NESTED_TYPEDEF_TPL(                                                            \
+        nested                                                                                  \
+      , boost::numeric::functional::detail::lvalue_of<Left>() Op                                \
+        boost::numeric::functional::detail::lvalue_of<Right>()                                  \
+    )                                                                                           \
+    typedef typename nested::type type;                                                         \
+    /**/
+
+    /// INTERNAL ONLY
+    ///
+#define BOOST_NUMERIC_FUNCTIONAL_LEFT(Left, Op, Right)                                          \
+    typedef Left &type;                                                                         \
+    /**/
+
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(plus, +, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(minus, -, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(multiplies, *, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(divides, /, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(modulus, %, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(greater, >, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(greater_equal, >=, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(less, <, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(less_equal, <=, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(equal_to, ==, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(not_equal_to, !=, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
+
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(assign, =, BOOST_NUMERIC_FUNCTIONAL_LEFT)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(plus_assign, +=, BOOST_NUMERIC_FUNCTIONAL_LEFT)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(minus_assign, -=, BOOST_NUMERIC_FUNCTIONAL_LEFT)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(multiplies_assign, *=, BOOST_NUMERIC_FUNCTIONAL_LEFT)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(divides_assign, /=, BOOST_NUMERIC_FUNCTIONAL_LEFT)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(modulus_assign, %=, BOOST_NUMERIC_FUNCTIONAL_LEFT)
+
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_UNARY_OP(unary_plus, +)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_UNARY_OP(unary_minus, -)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_UNARY_OP(complement, ~)
+    BOOST_NUMERIC_FUNCTIONAL_DEFINE_UNARY_OP(logical_not, !)
+
+#undef BOOST_NUMERIC_FUNCTIONAL_LEFT
+#undef BOOST_NUMERIC_FUNCTIONAL_DEDUCED
+#undef BOOST_NUMERIC_FUNCTIONAL_DEFINE_UNARY_OP
+#undef BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP
+
+    namespace functional
+    {
+        template<typename Left, typename Right, typename EnableIf>
+        struct min_assign_base
+          : std::binary_function<Left, Right, void>
+        {
+            void operator ()(Left &left, Right &right) const
+            {
+                if(numeric::less(right, left))
+                {
+                    left = right;
+                }
+            }
+        };
+
+        template<typename Left, typename Right, typename EnableIf>
+        struct max_assign_base
+          : std::binary_function<Left, Right, void>
+        {
+            void operator ()(Left &left, Right &right) const
+            {
+                if(numeric::greater(right, left))
+                {
+                    left = right;
+                }
+            }
+        };
+
+        template<typename Left, typename Right, typename EnableIf>
+        struct average_base
+          : functional::divides<Left, Right>
+        {};
+
+        // partial specialization that promotes the arguments to double for
+        // integral division.
+        template<typename Left, typename Right>
+        struct average_base<Left, Right, typename enable_if<are_integral<Left, Right> >::type>
+          : functional::divides<double const, double const>
+        {};
+
+        template<typename To, typename From, typename EnableIf>
+        struct promote_base
+          : std::unary_function<From, To>
+        {
+            To operator ()(From &from) const
+            {
+                return from;
+            }
+        };
+
+        template<typename ToFrom>
+        struct promote_base<ToFrom, ToFrom, void>
+          : std::unary_function<ToFrom, ToFrom>
+        {
+            ToFrom &operator ()(ToFrom &tofrom)
+            {
+                return tofrom;
+            }
+        };
+
+        template<typename Arg, typename EnableIf>
+        struct as_min_base
+          : std::unary_function<Arg, typename remove_const<Arg>::type>
+        {
+            typename remove_const<Arg>::type operator ()(Arg &) const
+            {
+                return (std::numeric_limits<typename remove_const<Arg>::type>::min)();
+            }
+        };
+
+        template<typename Arg>
+        struct as_min_base<Arg, typename enable_if<is_floating_point<Arg> >::type>
+          : std::unary_function<Arg, typename remove_const<Arg>::type>
+        {
+            typename remove_const<Arg>::type operator ()(Arg &) const
+            {
+                return -(std::numeric_limits<typename remove_const<Arg>::type>::max)();
+            }
+        };
+
+        template<typename Arg, typename EnableIf>
+        struct as_max_base
+          : std::unary_function<Arg, typename remove_const<Arg>::type>
+        {
+            typename remove_const<Arg>::type operator ()(Arg &) const
+            {
+                return (std::numeric_limits<typename remove_const<Arg>::type>::max)();
+            }
+        };
+
+        template<typename Arg, typename EnableIf>
+        struct as_zero_base
+          : std::unary_function<Arg, typename remove_const<Arg>::type>
+        {
+            typename remove_const<Arg>::type operator ()(Arg &) const
+            {
+                return numeric::zero<typename remove_const<Arg>::type>::value;
+            }
+        };
+
+        template<typename Arg, typename EnableIf>
+        struct as_one_base
+          : std::unary_function<Arg, typename remove_const<Arg>::type>
+        {
+            typename remove_const<Arg>::type operator ()(Arg &) const
+            {
+                return numeric::one<typename remove_const<Arg>::type>::value;
+            }
+        };
+
+        template<typename To, typename From, typename ToTag, typename FromTag>
+        struct promote
+          : promote_base<To, From, void>
+        {};
+
+        template<typename Left, typename Right, typename LeftTag, typename RightTag>
+        struct min_assign
+          : min_assign_base<Left, Right, void>
+        {};
+
+        template<typename Left, typename Right, typename LeftTag, typename RightTag>
+        struct max_assign
+          : max_assign_base<Left, Right, void>
+        {};
+
+        template<typename Left, typename Right, typename LeftTag, typename RightTag>
+        struct average
+          : average_base<Left, Right, void>
+        {};
+
+        template<typename Arg, typename Tag>
+        struct as_min
+          : as_min_base<Arg, void>
+        {};
+
+        template<typename Arg, typename Tag>
+        struct as_max
+          : as_max_base<Arg, void>
+        {};
+
+        template<typename Arg, typename Tag>
+        struct as_zero
+          : as_zero_base<Arg, void>
+        {};
+
+        template<typename Arg, typename Tag>
+        struct as_one
+          : as_one_base<Arg, void>
+        {};
+    }
+
+    namespace op
+    {
+        template<typename To>
+        struct promote
+          : boost::detail::function1<functional::promote<To, _, typename functional::tag<To>::type, functional::tag<_> > >
+        {};
+
+        struct min_assign
+          : boost::detail::function2<functional::min_assign<_1, _2, functional::tag<_1>, functional::tag<_2> > >
+        {};
+
+        struct max_assign
+          : boost::detail::function2<functional::max_assign<_1, _2, functional::tag<_1>, functional::tag<_2> > >
+        {};
+
+        struct average
+          : boost::detail::function2<functional::average<_1, _2, functional::tag<_1>, functional::tag<_2> > >
+        {};
+
+        struct as_min
+          : boost::detail::function1<functional::as_min<_, functional::tag<_> > >
+        {};
+
+        struct as_max
+          : boost::detail::function1<functional::as_max<_, functional::tag<_> > >
+        {};
+
+        struct as_zero
+          : boost::detail::function1<functional::as_zero<_, functional::tag<_> > >
+        {};
+
+        struct as_one
+          : boost::detail::function1<functional::as_one<_, functional::tag<_> > >
+        {};
+    }
+
+    namespace
+    {
+        op::min_assign const &min_assign = boost::detail::pod_singleton<op::min_assign>::instance;
+        op::max_assign const &max_assign = boost::detail::pod_singleton<op::max_assign>::instance;
+        op::average const &average = boost::detail::pod_singleton<op::average>::instance;
+        op::as_min const &as_min = boost::detail::pod_singleton<op::as_min>::instance;
+        op::as_max const &as_max = boost::detail::pod_singleton<op::as_max>::instance;
+        op::as_zero const &as_zero = boost::detail::pod_singleton<op::as_zero>::instance;
+        op::as_one const &as_one = boost::detail::pod_singleton<op::as_one>::instance;
+    }
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // promote
+    template<typename To, typename From>
+    typename lazy_disable_if<is_const<From>, mpl::if_<is_same<To, From>, To &, To> >::type
+    promote(From &from)
+    {
+        return functional::promote<To, From>()(from);
+    }
+
+    template<typename To, typename From>
+    typename mpl::if_<is_same<To const, From const>, To const &, To const>::type
+    promote(From const &from)
+    {
+        return functional::promote<To const, From const>()(from);
+    }
+
+    template<typename T>
+    struct default_
+    {
+        typedef default_ type;
+        typedef T value_type;
+        static T const value;
+
+        operator T const & () const
+        {
+            return default_::value;
+        }
+    };
+
+    template<typename T>
+    T const default_<T>::value = T();
+
+    template<typename T>
+    struct one
+    {
+        typedef one type;
+        typedef T value_type;
+        static T const value;
+
+        operator T const & () const
+        {
+            return one::value;
+        }
+    };
+
+    template<typename T>
+    T const one<T>::value = T(1);
+
+    template<typename T>
+    struct zero
+    {
+        typedef zero type;
+        typedef T value_type;
+        static T const value;
+
+        operator T const & () const
+        {
+            return zero::value;
+        }
+    };
+
+    template<typename T>
+    T const zero<T>::value = T();
+
+    template<typename T>
+    struct one_or_default
+      : mpl::if_<is_empty<T>, default_<T>, one<T> >::type
+    {};
+
+    template<typename T>
+    struct zero_or_default
+      : mpl::if_<is_empty<T>, default_<T>, zero<T> >::type
+    {};
+
+}} // namespace boost::numeric
+
+#endif
diff --git a/boost/accumulators/numeric/functional/complex.hpp b/boost/accumulators/numeric/functional/complex.hpp
new file mode 100644
index 0000000..ea8c033
--- /dev/null
+++ b/boost/accumulators/numeric/functional/complex.hpp
@@ -0,0 +1,82 @@
+///////////////////////////////////////////////////////////////////////////////
+/// \file complex.hpp
+///
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_NUMERIC_FUNCTIONAL_COMPLEX_HPP_EAN_01_17_2006
+#define BOOST_NUMERIC_FUNCTIONAL_COMPLEX_HPP_EAN_01_17_2006
+
+#ifdef BOOST_NUMERIC_FUNCTIONAL_HPP_INCLUDED
+# error Include this file before boost/accumulators/numeric/functional.hpp
+#endif
+
+#include <complex>
+#include <boost/mpl/or.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/utility/enable_if.hpp>
+#include <boost/typeof/std/complex.hpp>
+#include <boost/accumulators/numeric/functional_fwd.hpp>
+
+namespace boost { namespace numeric { namespace operators
+{
+    // So that the stats compile when Sample type is std::complex
+    template<typename T, typename U>
+    typename
+        disable_if<
+            mpl::or_<is_same<T, U>, is_same<std::complex<T>, U> >
+          , std::complex<T>
+        >::type
+    operator *(std::complex<T> ri, U const &u)
+    {
+        // BUGBUG promote result to typeof(T()*u) ?
+        return ri *= static_cast<T>(u);
+    }
+
+    template<typename T, typename U>
+    typename
+        disable_if<
+            mpl::or_<is_same<T, U>, is_same<std::complex<T>, U> >
+          , std::complex<T>
+        >::type
+    operator /(std::complex<T> ri, U const &u)
+    {
+        // BUGBUG promote result to typeof(T()*u) ?
+        return ri /= static_cast<T>(u);
+    }
+
+}}} // namespace boost::numeric::operators
+
+namespace boost { namespace numeric
+{
+    namespace detail
+    {
+        template<typename T>
+        struct one_complex
+        {
+            static std::complex<T> const value;
+        };
+
+        template<typename T>
+        std::complex<T> const one_complex<T>::value
+          = std::complex<T>(numeric::one<T>::value, numeric::one<T>::value);
+    }
+
+    /// INTERNAL ONLY
+    ///
+    template<typename T>
+    struct one<std::complex<T> >
+      : detail::one_complex<T>
+    {
+        typedef one type;
+        typedef std::complex<T> value_type;
+        operator value_type const & () const
+        {
+            return detail::one_complex<T>::value;
+        }
+    };
+
+}} // namespace boost::numeric
+
+#endif
diff --git a/boost/accumulators/numeric/functional/valarray.hpp b/boost/accumulators/numeric/functional/valarray.hpp
new file mode 100644
index 0000000..41766a0
--- /dev/null
+++ b/boost/accumulators/numeric/functional/valarray.hpp
@@ -0,0 +1,360 @@
+///////////////////////////////////////////////////////////////////////////////
+/// \file valarray.hpp
+///
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_NUMERIC_FUNCTIONAL_VALARRAY_HPP_EAN_12_12_2005
+#define BOOST_NUMERIC_FUNCTIONAL_VALARRAY_HPP_EAN_12_12_2005
+
+#ifdef BOOST_NUMERIC_FUNCTIONAL_HPP_INCLUDED
+# error Include this file before boost/accumulators/numeric/functional.hpp
+#endif
+
+#include <valarray>
+#include <functional>
+#include <boost/assert.hpp>
+#include <boost/mpl/and.hpp>
+#include <boost/mpl/not.hpp>
+#include <boost/mpl/assert.hpp>
+#include <boost/utility/enable_if.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/type_traits/is_scalar.hpp>
+#include <boost/type_traits/remove_const.hpp>
+#include <boost/typeof/std/valarray.hpp>
+#include <boost/accumulators/numeric/functional_fwd.hpp>
+
+namespace boost { namespace numeric
+{
+    namespace operators
+    {
+        namespace acc_detail
+        {
+            template<typename Fun>
+            struct make_valarray
+            {
+                typedef std::valarray<typename Fun::result_type> type;
+            };
+        }
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // Handle valarray<Left> / Right where Right is a scalar and Right != Left.
+        template<typename Left, typename Right>
+        typename lazy_enable_if<
+            mpl::and_<is_scalar<Right>, mpl::not_<is_same<Left, Right> > >
+          , acc_detail::make_valarray<functional::divides<Left, Right> >
+        >::type
+        operator /(std::valarray<Left> const &left, Right const &right)
+        {
+            typedef typename functional::divides<Left, Right>::result_type value_type;
+            std::valarray<value_type> result(left.size());
+            for(std::size_t i = 0, size = result.size(); i != size; ++i)
+            {
+                result[i] = numeric::divides(left[i], right);
+            }
+            return result;
+        }
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // Handle valarray<Left> * Right where Right is a scalar and Right != Left.
+        template<typename Left, typename Right>
+        typename lazy_enable_if<
+            mpl::and_<is_scalar<Right>, mpl::not_<is_same<Left, Right> > >
+          , acc_detail::make_valarray<functional::multiplies<Left, Right> >
+        >::type
+        operator *(std::valarray<Left> const &left, Right const &right)
+        {
+            typedef typename functional::multiplies<Left, Right>::result_type value_type;
+            std::valarray<value_type> result(left.size());
+            for(std::size_t i = 0, size = result.size(); i != size; ++i)
+            {
+                result[i] = numeric::multiplies(left[i], right);
+            }
+            return result;
+        }
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // Handle valarray<Left> + valarray<Right> where Right != Left.
+        template<typename Left, typename Right>
+        typename lazy_disable_if<
+            is_same<Left, Right>
+          , acc_detail::make_valarray<functional::plus<Left, Right> >
+        >::type
+        operator +(std::valarray<Left> const &left, std::valarray<Right> const &right)
+        {
+            typedef typename functional::plus<Left, Right>::result_type value_type;
+            std::valarray<value_type> result(left.size());
+            for(std::size_t i = 0, size = result.size(); i != size; ++i)
+            {
+                result[i] = numeric::plus(left[i], right[i]);
+            }
+            return result;
+        }
+    }
+
+    namespace functional
+    {
+        struct std_valarray_tag;
+
+        template<typename T>
+        struct tag<std::valarray<T> >
+        {
+            typedef std_valarray_tag type;
+        };
+
+    #ifdef __GLIBCXX__
+        template<typename T, typename U>
+        struct tag<std::_Expr<T, U> >
+        {
+            typedef std_valarray_tag type;
+        };
+    #endif
+
+        /// INTERNAL ONLY
+        ///
+        // This is necessary because the GCC stdlib uses expression templates, and
+        // typeof(som-valarray-expression) is not an instance of std::valarray
+    #define BOOST_NUMERIC_FUNCTIONAL_DEFINE_VALARRAY_BIN_OP(Name, Op)                   \
+        template<typename Left, typename Right>                                         \
+        struct Name<Left, Right, std_valarray_tag, std_valarray_tag>                    \
+          : std::binary_function<                                                       \
+                Left                                                                    \
+              , Right                                                                   \
+              , std::valarray<                                                          \
+                    typename Name<                                                      \
+                        typename Left::value_type                                       \
+                      , typename Right::value_type                                      \
+                    >::result_type                                                      \
+                >                                                                       \
+            >                                                                           \
+        {                                                                               \
+            typedef typename Left::value_type left_value_type;                          \
+            typedef typename Right::value_type right_value_type;                        \
+            typedef                                                                     \
+                std::valarray<                                                          \
+                    typename Name<left_value_type, right_value_type>::result_type       \
+                >                                                                       \
+            result_type;                                                                \
+            result_type                                                                 \
+            operator ()(Left &left, Right &right) const                                 \
+            {                                                                           \
+                return numeric::promote<std::valarray<left_value_type> >(left)          \
+                    Op numeric::promote<std::valarray<right_value_type> >(right);       \
+            }                                                                           \
+        };                                                                              \
+        template<typename Left, typename Right>                                         \
+        struct Name<Left, Right, std_valarray_tag, void>                                \
+          : std::binary_function<                                                       \
+                Left                                                                    \
+              , Right                                                                   \
+              , std::valarray<                                                          \
+                    typename Name<typename Left::value_type, Right>::result_type        \
+                >                                                                       \
+            >                                                                           \
+        {                                                                               \
+            typedef typename Left::value_type left_value_type;                          \
+            typedef                                                                     \
+                std::valarray<                                                          \
+                    typename Name<left_value_type, Right>::result_type                  \
+                >                                                                       \
+            result_type;                                                                \
+            result_type                                                                 \
+            operator ()(Left &left, Right &right) const                                 \
+            {                                                                           \
+                return numeric::promote<std::valarray<left_value_type> >(left) Op right;\
+            }                                                                           \
+        };                                                                              \
+        template<typename Left, typename Right>                                         \
+        struct Name<Left, Right, void, std_valarray_tag>                                \
+          : std::binary_function<                                                       \
+                Left                                                                    \
+              , Right                                                                   \
+              , std::valarray<                                                          \
+                    typename Name<Left, typename Right::value_type>::result_type        \
+                >                                                                       \
+            >                                                                           \
+        {                                                                               \
+            typedef typename Right::value_type right_value_type;                        \
+            typedef                                                                     \
+                std::valarray<                                                          \
+                    typename Name<Left, right_value_type>::result_type                  \
+                >                                                                       \
+            result_type;                                                                \
+            result_type                                                                 \
+            operator ()(Left &left, Right &right) const                                 \
+            {                                                                           \
+                return left Op numeric::promote<std::valarray<right_value_type> >(right);\
+            }                                                                           \
+        };
+
+        BOOST_NUMERIC_FUNCTIONAL_DEFINE_VALARRAY_BIN_OP(plus, +)
+        BOOST_NUMERIC_FUNCTIONAL_DEFINE_VALARRAY_BIN_OP(minus, -)
+        BOOST_NUMERIC_FUNCTIONAL_DEFINE_VALARRAY_BIN_OP(multiplies, *)
+        BOOST_NUMERIC_FUNCTIONAL_DEFINE_VALARRAY_BIN_OP(divides, /)
+        BOOST_NUMERIC_FUNCTIONAL_DEFINE_VALARRAY_BIN_OP(modulus, %)
+
+    #undef BOOST_NUMERIC_FUNCTIONAL_DEFINE_VALARRAY_BIN_OP
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // element-wise min of std::valarray
+        template<typename Left, typename Right>
+        struct min_assign<Left, Right, std_valarray_tag, std_valarray_tag>
+          : std::binary_function<Left, Right, void>
+        {
+            void operator ()(Left &left, Right &right) const
+            {
+                BOOST_ASSERT(left.size() == right.size());
+                for(std::size_t i = 0, size = left.size(); i != size; ++i)
+                {
+                    if(numeric::less(right[i], left[i]))
+                    {
+                        left[i] = right[i];
+                    }
+                }
+            }
+        };
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // element-wise max of std::valarray
+        template<typename Left, typename Right>
+        struct max_assign<Left, Right, std_valarray_tag, std_valarray_tag>
+          : std::binary_function<Left, Right, void>
+        {
+            void operator ()(Left &left, Right &right) const
+            {
+                BOOST_ASSERT(left.size() == right.size());
+                for(std::size_t i = 0, size = left.size(); i != size; ++i)
+                {
+                    if(numeric::greater(right[i], left[i]))
+                    {
+                        left[i] = right[i];
+                    }
+                }
+            }
+        };
+
+        // partial specialization of numeric::average<> for std::valarray.
+        template<typename Left, typename Right, typename RightTag>
+        struct average<Left, Right, std_valarray_tag, RightTag>
+          : mpl::if_<
+                are_integral<typename Left::value_type, Right>
+              , divides<Left, double const>
+              , divides<Left, Right>
+            >::type
+        {};
+
+        // promote
+        template<typename To, typename From>
+        struct promote<To, From, std_valarray_tag, std_valarray_tag>
+          : std::unary_function<From, To>
+        {
+            To operator ()(From &arr) const
+            {
+                typename remove_const<To>::type res(arr.size());
+                for(std::size_t i = 0, size = arr.size(); i != size; ++i)
+                {
+                    res[i] = numeric::promote<typename To::value_type>(arr[i]);
+                }
+                return res;
+            }
+        };
+
+        template<typename ToFrom>
+        struct promote<ToFrom, ToFrom, std_valarray_tag, std_valarray_tag>
+          : std::unary_function<ToFrom, ToFrom>
+        {
+            ToFrom &operator ()(ToFrom &tofrom) const
+            {
+                return tofrom;
+            }
+        };
+
+        // for "promoting" a std::valarray<bool> to a bool, useful for
+        // comparing 2 valarrays for equality:
+        //   if(numeric::promote<bool>(a == b))
+        template<typename From>
+        struct promote<bool, From, void, std_valarray_tag>
+          : std::unary_function<From, bool>
+        {
+            bool operator ()(From &arr) const
+            {
+                BOOST_MPL_ASSERT((is_same<bool, typename From::value_type>));
+                for(std::size_t i = 0, size = arr.size(); i != size; ++i)
+                {
+                    if(!arr[i])
+                    {
+                        return false;
+                    }
+                }
+                return true;
+            }
+        };
+
+        template<typename From>
+        struct promote<bool const, From, void, std_valarray_tag>
+          : promote<bool, From, void, std_valarray_tag>
+        {};
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // functional::as_min
+        template<typename T>
+        struct as_min<T, std_valarray_tag>
+            : std::unary_function<T, typename remove_const<T>::type>
+        {
+            typename remove_const<T>::type operator ()(T &arr) const
+            {
+                return 0 == arr.size()
+                  ? T()
+                  : T(numeric::as_min(arr[0]), arr.size());
+            }
+        };
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // functional::as_max
+        template<typename T>
+        struct as_max<T, std_valarray_tag>
+          : std::unary_function<T, typename remove_const<T>::type>
+        {
+            typename remove_const<T>::type operator ()(T &arr) const
+            {
+                return 0 == arr.size()
+                  ? T()
+                  : T(numeric::as_max(arr[0]), arr.size());
+            }
+        };
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // functional::as_zero
+        template<typename T>
+        struct as_zero<T, std_valarray_tag>
+          : std::unary_function<T, typename remove_const<T>::type>
+        {
+            typename remove_const<T>::type operator ()(T &arr) const
+            {
+                return 0 == arr.size()
+                  ? T()
+                  : T(numeric::as_zero(arr[0]), arr.size());
+            }
+        };
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // functional::as_one
+        template<typename T>
+        struct as_one<T, std_valarray_tag>
+          : std::unary_function<T, typename remove_const<T>::type>
+        {
+            typename remove_const<T>::type operator ()(T &arr) const
+            {
+                return 0 == arr.size()
+                  ? T()
+                  : T(numeric::as_one(arr[0]), arr.size());
+            }
+        };
+
+    } // namespace functional
+
+}} // namespace boost::numeric
+
+#endif
+
diff --git a/boost/accumulators/numeric/functional/vector.hpp b/boost/accumulators/numeric/functional/vector.hpp
new file mode 100644
index 0000000..cdb2342
--- /dev/null
+++ b/boost/accumulators/numeric/functional/vector.hpp
@@ -0,0 +1,329 @@
+///////////////////////////////////////////////////////////////////////////////
+/// \file vector.hpp
+///
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_NUMERIC_FUNCTIONAL_VECTOR_HPP_EAN_12_12_2005
+#define BOOST_NUMERIC_FUNCTIONAL_VECTOR_HPP_EAN_12_12_2005
+
+#ifdef BOOST_NUMERIC_FUNCTIONAL_HPP_INCLUDED
+# error Include this file before boost/accumulators/numeric/functional.hpp
+#endif
+
+#include <vector>
+#include <functional>
+#include <boost/assert.hpp>
+#include <boost/mpl/and.hpp>
+#include <boost/mpl/not.hpp>
+#include <boost/utility/enable_if.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/type_traits/is_scalar.hpp>
+#include <boost/type_traits/remove_const.hpp>
+#include <boost/typeof/std/vector.hpp>
+#include <boost/accumulators/numeric/functional_fwd.hpp>
+
+namespace boost { namespace numeric
+{
+    namespace operators
+    {
+        namespace acc_detail
+        {
+            template<typename Fun>
+            struct make_vector
+            {
+                typedef std::vector<typename Fun::result_type> type;
+            };
+        }
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // Handle vector<Left> / Right where Right is a scalar.
+        template<typename Left, typename Right>
+        typename lazy_enable_if<
+            is_scalar<Right>
+          , acc_detail::make_vector<functional::divides<Left, Right> >
+        >::type
+        operator /(std::vector<Left> const &left, Right const &right)
+        {
+            typedef typename functional::divides<Left, Right>::result_type value_type;
+            std::vector<value_type> result(left.size());
+            for(std::size_t i = 0, size = result.size(); i != size; ++i)
+            {
+                result[i] = numeric::divides(left[i], right);
+            }
+            return result;
+        }
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // Handle vector<Left> / vector<Right>.
+        template<typename Left, typename Right>
+        std::vector<typename functional::divides<Left, Right>::result_type>
+        operator /(std::vector<Left> const &left, std::vector<Right> const &right)
+        {
+            typedef typename functional::divides<Left, Right>::result_type value_type;
+            std::vector<value_type> result(left.size());
+            for(std::size_t i = 0, size = result.size(); i != size; ++i)
+            {
+                result[i] = numeric::divides(left[i], right[i]);
+            }
+            return result;
+        }
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // Handle vector<Left> * Right where Right is a scalar.
+        template<typename Left, typename Right>
+        typename lazy_enable_if<
+            is_scalar<Right>
+          , acc_detail::make_vector<functional::multiplies<Left, Right> >
+        >::type
+        operator *(std::vector<Left> const &left, Right const &right)
+        {
+            typedef typename functional::multiplies<Left, Right>::result_type value_type;
+            std::vector<value_type> result(left.size());
+            for(std::size_t i = 0, size = result.size(); i != size; ++i)
+            {
+                result[i] = numeric::multiplies(left[i], right);
+            }
+            return result;
+        }
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // Handle Left * vector<Right> where Left is a scalar.
+        template<typename Left, typename Right>
+        typename lazy_enable_if<
+            is_scalar<Left>
+          , acc_detail::make_vector<functional::multiplies<Left, Right> >
+        >::type
+        operator *(Left const &left, std::vector<Right> const &right)
+        {
+            typedef typename functional::multiplies<Left, Right>::result_type value_type;
+            std::vector<value_type> result(right.size());
+            for(std::size_t i = 0, size = result.size(); i != size; ++i)
+            {
+                result[i] = numeric::multiplies(left, right[i]);
+            }
+            return result;
+        }
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // Handle vector<Left> * vector<Right>
+        template<typename Left, typename Right>
+        std::vector<typename functional::multiplies<Left, Right>::result_type>
+        operator *(std::vector<Left> const &left, std::vector<Right> const &right)
+        {
+            typedef typename functional::multiplies<Left, Right>::result_type value_type;
+            std::vector<value_type> result(left.size());
+            for(std::size_t i = 0, size = result.size(); i != size; ++i)
+            {
+                result[i] = numeric::multiplies(left[i], right[i]);
+            }
+            return result;
+        }
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // Handle vector<Left> + vector<Right>
+        template<typename Left, typename Right>
+        std::vector<typename functional::plus<Left, Right>::result_type>
+        operator +(std::vector<Left> const &left, std::vector<Right> const &right)
+        {
+            typedef typename functional::plus<Left, Right>::result_type value_type;
+            std::vector<value_type> result(left.size());
+            for(std::size_t i = 0, size = result.size(); i != size; ++i)
+            {
+                result[i] = numeric::plus(left[i], right[i]);
+            }
+            return result;
+        }
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // Handle vector<Left> - vector<Right>
+        template<typename Left, typename Right>
+        std::vector<typename functional::minus<Left, Right>::result_type>
+        operator -(std::vector<Left> const &left, std::vector<Right> const &right)
+        {
+            typedef typename functional::minus<Left, Right>::result_type value_type;
+            std::vector<value_type> result(left.size());
+            for(std::size_t i = 0, size = result.size(); i != size; ++i)
+            {
+                result[i] = numeric::minus(left[i], right[i]);
+            }
+            return result;
+        }
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // Handle vector<Left> += vector<Left>
+        template<typename Left>
+        std::vector<Left> &
+        operator +=(std::vector<Left> &left, std::vector<Left> const &right)
+        {
+            BOOST_ASSERT(left.size() == right.size());
+            for(std::size_t i = 0, size = left.size(); i != size; ++i)
+            {
+                numeric::plus_assign(left[i], right[i]);
+            }
+            return left;
+        }
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // Handle -vector<Arg>
+        template<typename Arg>
+        std::vector<typename functional::unary_minus<Arg>::result_type>
+        operator -(std::vector<Arg> const &arg)
+        {
+            typedef typename functional::unary_minus<Arg>::result_type value_type;
+            std::vector<value_type> result(arg.size());
+            for(std::size_t i = 0, size = result.size(); i != size; ++i)
+            {
+                result[i] = numeric::unary_minus(arg[i]);
+            }
+            return result;
+        }
+    }
+
+    namespace functional
+    {
+        struct std_vector_tag;
+
+        template<typename T, typename Al>
+        struct tag<std::vector<T, Al> >
+        {
+            typedef std_vector_tag type;
+        };
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // element-wise min of std::vector
+        template<typename Left, typename Right>
+        struct min_assign<Left, Right, std_vector_tag, std_vector_tag>
+          : std::binary_function<Left, Right, void>
+        {
+            void operator ()(Left &left, Right &right) const
+            {
+                BOOST_ASSERT(left.size() == right.size());
+                for(std::size_t i = 0, size = left.size(); i != size; ++i)
+                {
+                    if(numeric::less(right[i], left[i]))
+                    {
+                        left[i] = right[i];
+                    }
+                }
+            }
+        };
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // element-wise max of std::vector
+        template<typename Left, typename Right>
+        struct max_assign<Left, Right, std_vector_tag, std_vector_tag>
+          : std::binary_function<Left, Right, void>
+        {
+            void operator ()(Left &left, Right &right) const
+            {
+                BOOST_ASSERT(left.size() == right.size());
+                for(std::size_t i = 0, size = left.size(); i != size; ++i)
+                {
+                    if(numeric::greater(right[i], left[i]))
+                    {
+                        left[i] = right[i];
+                    }
+                }
+            }
+        };
+
+        // partial specialization for std::vector.
+        template<typename Left, typename Right>
+        struct average<Left, Right, std_vector_tag, void>
+          : mpl::if_<
+                are_integral<typename Left::value_type, Right>
+              , divides<Left, double const>
+              , divides<Left, Right>
+            >::type
+        {};
+
+        // promote
+        template<typename To, typename From>
+        struct promote<To, From, std_vector_tag, std_vector_tag>
+          : std::unary_function<From, To>
+        {
+            To operator ()(From &arr) const
+            {
+                typename remove_const<To>::type res(arr.size());
+                for(std::size_t i = 0, size = arr.size(); i != size; ++i)
+                {
+                    res[i] = numeric::promote<typename To::value_type>(arr[i]);
+                }
+                return res;
+            }
+        };
+
+        template<typename ToFrom>
+        struct promote<ToFrom, ToFrom, std_vector_tag, std_vector_tag>
+          : std::unary_function<ToFrom, ToFrom>
+        {
+            ToFrom &operator ()(ToFrom &tofrom) const
+            {
+                return tofrom;
+            }
+        };
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // functional::as_min
+        template<typename T>
+        struct as_min<T, std_vector_tag>
+          : std::unary_function<T, typename remove_const<T>::type>
+        {
+            typename remove_const<T>::type operator ()(T &arr) const
+            {
+                return 0 == arr.size()
+                  ? T()
+                  : T(arr.size(), numeric::as_min(arr[0]));
+            }
+        };
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // functional::as_max
+        template<typename T>
+        struct as_max<T, std_vector_tag>
+          : std::unary_function<T, typename remove_const<T>::type>
+        {
+            typename remove_const<T>::type operator ()(T &arr) const
+            {
+                return 0 == arr.size()
+                  ? T()
+                  : T(arr.size(), numeric::as_max(arr[0]));
+            }
+        };
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // functional::as_zero
+        template<typename T>
+        struct as_zero<T, std_vector_tag>
+          : std::unary_function<T, typename remove_const<T>::type>
+        {
+            typename remove_const<T>::type operator ()(T &arr) const
+            {
+                return 0 == arr.size()
+                  ? T()
+                  : T(arr.size(), numeric::as_zero(arr[0]));
+            }
+        };
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // functional::as_one
+        template<typename T>
+        struct as_one<T, std_vector_tag>
+          : std::unary_function<T, typename remove_const<T>::type>
+        {
+            typename remove_const<T>::type operator ()(T &arr) const
+            {
+                return 0 == arr.size()
+                  ? T()
+                  : T(arr.size(), numeric::as_one(arr[0]));
+            }
+        };
+
+    } // namespace functional
+
+}} // namespace boost::numeric
+
+#endif
+
diff --git a/boost/accumulators/numeric/functional_fwd.hpp b/boost/accumulators/numeric/functional_fwd.hpp
new file mode 100644
index 0000000..940d15b
--- /dev/null
+++ b/boost/accumulators/numeric/functional_fwd.hpp
@@ -0,0 +1,221 @@
+///////////////////////////////////////////////////////////////////////////////
+/// \file functional_fwd.hpp
+///
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_NUMERIC_FUNCTIONAL_FWD_HPP_EAN_08_12_2005
+#define BOOST_NUMERIC_FUNCTIONAL_FWD_HPP_EAN_08_12_2005
+
+#include <boost/mpl/if.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/utility/enable_if.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/type_traits/is_const.hpp>
+
+namespace boost { namespace numeric
+{
+    // For using directives -- this namespace may be re-opened elsewhere
+    namespace operators
+    {}
+
+    namespace op
+    {
+        using mpl::_;
+        using mpl::_1;
+        using mpl::_2;
+    }
+
+    namespace functional
+    {
+        using namespace operators;
+
+        template<typename T>
+        struct tag
+        {
+            typedef void type;
+        };
+
+        template<typename T>
+        struct tag<T const>
+          : tag<T>
+        {};
+
+        template<typename T>
+        struct tag<T volatile>
+          : tag<T>
+        {};
+
+        template<typename T>
+        struct tag<T const volatile>
+          : tag<T>
+        {};
+
+        template<typename T>
+        struct static_;
+
+        template<typename A0, typename A1>
+        struct are_integral;
+    }
+
+    /// INTERNAL ONLY
+    ///
+#define BOOST_NUMERIC_FUNCTIONAL_DECLARE_UNARY_OP(Name, Op)                                     \
+    namespace functional                                                                        \
+    {                                                                                           \
+        template<typename Arg, typename EnableIf = void>                                        \
+        struct Name ## _base;                                                                   \
+        template<typename Arg, typename ArgTag = typename tag<Arg>::type>                       \
+        struct Name;                                                                            \
+    }                                                                                           \
+    namespace op                                                                                \
+    {                                                                                           \
+        struct Name;                                                                            \
+    }                                                                                           \
+    namespace                                                                                   \
+    {                                                                                           \
+        extern op::Name const &Name;                                                            \
+    }
+
+    /// INTERNAL ONLY
+    ///
+#define BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(Name)                                        \
+    namespace functional                                                                        \
+    {                                                                                           \
+        template<typename Left, typename Right, typename EnableIf = void>                       \
+        struct result_of_ ## Name;                                                              \
+        template<typename Left, typename Right, typename EnableIf = void>                       \
+        struct Name ## _base;                                                                   \
+        template<                                                                               \
+            typename Left                                                                       \
+          , typename Right                                                                      \
+          , typename LeftTag = typename tag<Left>::type                                         \
+          , typename RightTag = typename tag<Right>::type                                       \
+        >                                                                                       \
+        struct Name;                                                                            \
+    }                                                                                           \
+    namespace op                                                                                \
+    {                                                                                           \
+        struct Name;                                                                            \
+    }                                                                                           \
+    namespace                                                                                   \
+    {                                                                                           \
+        extern op::Name const &Name;                                                            \
+    }
+
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(plus)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(minus)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(multiplies)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(divides)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(modulus)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(greater)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(greater_equal)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(less)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(less_equal)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(equal_to)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(not_equal_to)
+
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(assign)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(plus_assign)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(minus_assign)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(multiplies_assign)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(divides_assign)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP(modulus_assign)
+
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_UNARY_OP(unary_plus, +)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_UNARY_OP(unary_minus, -)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_UNARY_OP(complement, ~)
+    BOOST_NUMERIC_FUNCTIONAL_DECLARE_UNARY_OP(logical_not, !)
+
+#undef BOOST_NUMERIC_FUNCTIONAL_DECLARE_UNARY_OP
+#undef BOOST_NUMERIC_FUNCTIONAL_DECLARE_BINARY_OP
+
+
+    namespace functional
+    {
+        template<typename To, typename From, typename EnableIf = void>
+        struct promote_base;
+        template<typename Left, typename Right, typename EnableIf = void>
+        struct min_assign_base;
+        template<typename Left, typename Right, typename EnableIf = void>
+        struct max_assign_base;
+        template<typename Left, typename Right, typename EnableIf = void>
+        struct average_base;
+        template<typename Arg, typename EnableIf = void>
+        struct as_min_base;
+        template<typename Arg, typename EnableIf = void>
+        struct as_max_base;
+        template<typename Arg, typename EnableIf = void>
+        struct as_zero_base;
+        template<typename Arg, typename EnableIf = void>
+        struct as_one_base;
+
+        template<typename To, typename From, typename ToTag = typename tag<To>::type, typename FromTag = typename tag<From>::type>
+        struct promote;
+        template<typename Left, typename Right, typename LeftTag = typename tag<Left>::type, typename RightTag = typename tag<Right>::type>
+        struct min_assign;
+        template<typename Left, typename Right, typename LeftTag = typename tag<Left>::type, typename RightTag = typename tag<Right>::type>
+        struct max_assign;
+        template<typename Left, typename Right, typename LeftTag = typename tag<Left>::type, typename RightTag = typename tag<Right>::type>
+        struct average;
+        template<typename Arg, typename Tag = typename tag<Arg>::type>
+        struct as_min;
+        template<typename Arg, typename Tag = typename tag<Arg>::type>
+        struct as_max;
+        template<typename Arg, typename Tag = typename tag<Arg>::type>
+        struct as_zero;
+        template<typename Arg, typename Tag = typename tag<Arg>::type>
+        struct as_one;
+    }
+
+    namespace op
+    {
+        template<typename To>
+        struct promote;
+        struct min_assign;
+        struct max_assign;
+        struct average;
+        struct as_min;
+        struct as_max;
+        struct as_zero;
+        struct as_one;
+    }
+
+    namespace
+    {
+        extern op::min_assign const &min_assign;
+        extern op::max_assign const &max_assign;
+        extern op::average const &average;
+        extern op::as_min const &as_min;
+        extern op::as_max const &as_max;
+        extern op::as_zero const &as_zero;
+        extern op::as_one const &as_one;
+    }
+
+    template<typename To, typename From>
+    typename lazy_disable_if<is_const<From>, mpl::if_<is_same<To, From>, To &, To> >::type
+    promote(From &from);
+
+    template<typename To, typename From>
+    typename mpl::if_<is_same<To const, From const>, To const &, To const>::type
+    promote(From const &from);
+
+    template<typename T>
+    struct default_;
+
+    template<typename T>
+    struct one;
+
+    template<typename T>
+    struct zero;
+
+    template<typename T>
+    struct one_or_default;
+
+    template<typename T>
+    struct zero_or_default;
+
+}} // namespace boost::numeric
+
+#endif
diff --git a/boost/accumulators/statistics.hpp b/boost/accumulators/statistics.hpp
new file mode 100644
index 0000000..1d136e5
--- /dev/null
+++ b/boost/accumulators/statistics.hpp
@@ -0,0 +1,61 @@
+///////////////////////////////////////////////////////////////////////////////
+/// \file statistics.hpp
+/// Includes all of the Statistical Accumulators Library
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_HPP_EAN_01_17_2006
+#define BOOST_ACCUMULATORS_STATISTICS_HPP_EAN_01_17_2006
+
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/covariance.hpp>
+#include <boost/accumulators/statistics/density.hpp>
+#include <boost/accumulators/statistics/error_of.hpp>
+#include <boost/accumulators/statistics/error_of_mean.hpp>
+#include <boost/accumulators/statistics/extended_p_square.hpp>
+#include <boost/accumulators/statistics/extended_p_square_quantile.hpp>
+#include <boost/accumulators/statistics/kurtosis.hpp>
+#include <boost/accumulators/statistics/max.hpp>
+#include <boost/accumulators/statistics/mean.hpp>
+#include <boost/accumulators/statistics/median.hpp>
+#include <boost/accumulators/statistics/min.hpp>
+#include <boost/accumulators/statistics/moment.hpp>
+#include <boost/accumulators/statistics/peaks_over_threshold.hpp>
+#include <boost/accumulators/statistics/pot_tail_mean.hpp>
+#include <boost/accumulators/statistics/pot_quantile.hpp>
+#include <boost/accumulators/statistics/p_square_cumulative_distribution.hpp>
+#include <boost/accumulators/statistics/p_square_quantile.hpp>
+#include <boost/accumulators/statistics/skewness.hpp>
+#include <boost/accumulators/statistics/stats.hpp>
+#include <boost/accumulators/statistics/sum.hpp>
+#include <boost/accumulators/statistics/sum_kahan.hpp>
+#include <boost/accumulators/statistics/tail.hpp>
+#include <boost/accumulators/statistics/tail_quantile.hpp>
+#include <boost/accumulators/statistics/tail_mean.hpp>
+#include <boost/accumulators/statistics/tail_variate.hpp>
+#include <boost/accumulators/statistics/tail_variate_means.hpp>
+#include <boost/accumulators/statistics/variance.hpp>
+#include <boost/accumulators/statistics/weighted_covariance.hpp>
+#include <boost/accumulators/statistics/weighted_density.hpp>
+#include <boost/accumulators/statistics/weighted_kurtosis.hpp>
+#include <boost/accumulators/statistics/weighted_extended_p_square.hpp>
+#include <boost/accumulators/statistics/weighted_mean.hpp>
+#include <boost/accumulators/statistics/weighted_median.hpp>
+#include <boost/accumulators/statistics/weighted_moment.hpp>
+#include <boost/accumulators/statistics/weighted_peaks_over_threshold.hpp>
+#include <boost/accumulators/statistics/weighted_p_square_cumulative_distribution.hpp>
+#include <boost/accumulators/statistics/weighted_p_square_quantile.hpp>
+#include <boost/accumulators/statistics/weighted_skewness.hpp>
+#include <boost/accumulators/statistics/weighted_sum.hpp>
+#include <boost/accumulators/statistics/weighted_sum_kahan.hpp>
+#include <boost/accumulators/statistics/weighted_tail_quantile.hpp>
+#include <boost/accumulators/statistics/weighted_tail_mean.hpp>
+#include <boost/accumulators/statistics/weighted_tail_variate_means.hpp>
+#include <boost/accumulators/statistics/weighted_variance.hpp>
+#include <boost/accumulators/statistics/with_error.hpp>
+#include <boost/accumulators/statistics/parameters/quantile_probability.hpp>
+#include <boost/accumulators/statistics/variates/covariate.hpp>
+
+#endif
diff --git a/boost/accumulators/statistics/count.hpp b/boost/accumulators/statistics/count.hpp
new file mode 100644
index 0000000..6d30b41
--- /dev/null
+++ b/boost/accumulators/statistics/count.hpp
@@ -0,0 +1,80 @@
+///////////////////////////////////////////////////////////////////////////////
+// count.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_COUNT_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_COUNT_HPP_EAN_28_10_2005
+
+#include <boost/mpl/always.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // count_impl
+    struct count_impl
+      : accumulator_base
+    {
+        // for boost::result_of
+        typedef std::size_t result_type;
+
+        count_impl(dont_care)
+          : cnt(0)
+        {
+        }
+
+        void operator ()(dont_care)
+        {
+            ++this->cnt;
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->cnt;
+        }
+
+    private:
+        std::size_t cnt;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::count
+//
+namespace tag
+{
+    struct count
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef mpl::always<accumulators::impl::count_impl> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::count
+//
+namespace extract
+{
+    extractor<tag::count> const count = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(count)
+}
+
+using extract::count;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/covariance.hpp b/boost/accumulators/statistics/covariance.hpp
new file mode 100644
index 0000000..b34284b
--- /dev/null
+++ b/boost/accumulators/statistics/covariance.hpp
@@ -0,0 +1,220 @@
+///////////////////////////////////////////////////////////////////////////////
+// covariance.hpp
+//
+//  Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_COVARIANCE_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_COVARIANCE_HPP_DE_01_01_2006
+
+#include <vector>
+#include <limits>
+#include <numeric>
+#include <functional>
+#include <complex>
+#include <boost/mpl/assert.hpp>
+#include <boost/mpl/bool.hpp>
+#include <boost/range.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/numeric/ublas/io.hpp>
+#include <boost/numeric/ublas/matrix.hpp>
+#include <boost/type_traits/is_scalar.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/mean.hpp>
+
+namespace boost { namespace numeric
+{
+    namespace functional
+    {
+        struct std_vector_tag;
+
+        ///////////////////////////////////////////////////////////////////////////////
+        // functional::outer_product
+        template<typename Left, typename Right, typename EnableIf = void>
+        struct outer_product_base
+          : functional::multiplies<Left, Right>
+        {};
+
+        template<typename Left, typename Right, typename LeftTag = typename tag<Left>::type, typename RightTag = typename tag<Right>::type>
+        struct outer_product
+          : outer_product_base<Left, Right, void>
+        {};
+
+        template<typename Left, typename Right>
+        struct outer_product<Left, Right, std_vector_tag, std_vector_tag>
+          : std::binary_function<
+                Left
+              , Right
+              , ublas::matrix<
+                    typename functional::multiplies<
+                        typename Left::value_type
+                      , typename Right::value_type
+                    >::result_type
+                >
+            >
+        {
+            typedef
+                ublas::matrix<
+                    typename functional::multiplies<
+                        typename Left::value_type
+                      , typename Right::value_type
+                    >::result_type
+                >
+            result_type;
+
+            result_type
+            operator ()(Left & left, Right & right) const
+            {
+                std::size_t left_size = left.size();
+                std::size_t right_size = right.size();
+                result_type result(left_size, right_size);
+                for (std::size_t i = 0; i < left_size; ++i)
+                    for (std::size_t j = 0; j < right_size; ++j)
+                        result(i,j) = numeric::multiplies(left[i], right[j]);
+                return result;
+            }
+        };
+    }
+
+    namespace op
+    {
+        struct outer_product
+          : boost::detail::function2<functional::outer_product<_1, _2, functional::tag<_1>, functional::tag<_2> > >
+        {};
+    }
+
+    namespace
+    {
+        op::outer_product const &outer_product = boost::detail::pod_singleton<op::outer_product>::instance;
+    }
+
+}}
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // covariance_impl
+    //
+    /**
+        @brief Covariance Estimator
+
+        An iterative Monte Carlo estimator for the covariance \f$\mathrm{Cov}(X,X')\f$, where \f$X\f$ is a sample
+        and \f$X'\f$ is a variate, is given by:
+
+        \f[
+            \hat{c}_n = \frac{n-1}{n} \hat{c}_{n-1} + \frac{1}{n-1}(X_n - \hat{\mu}_n)(X_n' - \hat{\mu}_n'),\quad n\ge2,\quad\hat{c}_1 = 0,
+        \f]
+
+        \f$\hat{\mu}_n\f$ and \f$\hat{\mu}_n'\f$ being the means of the samples and variates.
+    */
+    template<typename Sample, typename VariateType, typename VariateTag>
+    struct covariance_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type sample_type;
+        typedef typename numeric::functional::average<VariateType, std::size_t>::result_type variate_type;
+        // for boost::result_of
+        typedef typename numeric::functional::outer_product<sample_type, variate_type>::result_type result_type;
+
+        template<typename Args>
+        covariance_impl(Args const &args)
+          : cov_(
+                numeric::outer_product(
+                    numeric::average(args[sample | Sample()], (std::size_t)1)
+                  , numeric::average(args[parameter::keyword<VariateTag>::get() | VariateType()], (std::size_t)1)
+                )
+            )
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            std::size_t cnt = count(args);
+
+            if (cnt > 1)
+            {
+                extractor<tag::mean_of_variates<VariateType, VariateTag> > const some_mean_of_variates = {};
+
+                this->cov_ = this->cov_*(cnt-1.)/cnt
+                           + numeric::outer_product(
+                                 some_mean_of_variates(args) - args[parameter::keyword<VariateTag>::get()]
+                               , mean(args) - args[sample]
+                             ) / (cnt-1.);
+            }
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->cov_;
+        }
+
+    private:
+        result_type cov_;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::covariance
+//
+namespace tag
+{
+    template<typename VariateType, typename VariateTag>
+    struct covariance
+      : depends_on<count, mean, mean_of_variates<VariateType, VariateTag> >
+    {
+        typedef accumulators::impl::covariance_impl<mpl::_1, VariateType, VariateTag> impl;
+    };
+
+    struct abstract_covariance
+      : depends_on<>
+    {
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::covariance
+//
+namespace extract
+{
+    extractor<tag::abstract_covariance> const covariance = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(covariance)
+}
+
+using extract::covariance;
+
+template<typename VariateType, typename VariateTag>
+struct feature_of<tag::covariance<VariateType, VariateTag> >
+  : feature_of<tag::abstract_covariance>
+{
+};
+
+// So that covariance can be automatically substituted with
+// weighted_covariance when the weight parameter is non-void.
+template<typename VariateType, typename VariateTag>
+struct as_weighted_feature<tag::covariance<VariateType, VariateTag> >
+{
+    typedef tag::weighted_covariance<VariateType, VariateTag> type;
+};
+
+template<typename VariateType, typename VariateTag>
+struct feature_of<tag::weighted_covariance<VariateType, VariateTag> >
+  : feature_of<tag::covariance<VariateType, VariateTag> >
+{};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/density.hpp b/boost/accumulators/statistics/density.hpp
new file mode 100644
index 0000000..8835f47
--- /dev/null
+++ b/boost/accumulators/statistics/density.hpp
@@ -0,0 +1,246 @@
+
+///////////////////////////////////////////////////////////////////////////////
+// density.hpp
+//
+//  Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_DENSITY_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_DENSITY_HPP_DE_01_01_2006
+
+#include <vector>
+#include <limits>
+#include <functional>
+#include <boost/range.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/max.hpp>
+#include <boost/accumulators/statistics/min.hpp>
+
+namespace boost { namespace accumulators
+{
+
+///////////////////////////////////////////////////////////////////////////////
+// cache_size and num_bins named parameters
+//
+BOOST_PARAMETER_NESTED_KEYWORD(tag, density_cache_size, cache_size)
+BOOST_PARAMETER_NESTED_KEYWORD(tag, density_num_bins, num_bins)
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // density_impl
+    //  density histogram
+    /**
+        @brief Histogram density estimator
+
+        The histogram density estimator returns a histogram of the sample distribution. The positions and sizes of the bins
+        are determined using a specifiable number of cached samples (cache_size). The range between the minimum and the
+        maximum of the cached samples is subdivided into a specifiable number of bins (num_bins) of same size. Additionally,
+        an under- and an overflow bin is added to capture future under- and overflow samples. Once the bins are determined,
+        the cached samples and all subsequent samples are added to the correct bins. At the end, a range of std::pair is
+        return, where each pair contains the position of the bin (lower bound) and the samples count (normalized with the
+        total number of samples).
+
+        @param  density_cache_size Number of first samples used to determine min and max.
+        @param  density_num_bins Number of bins (two additional bins collect under- and overflow samples).
+    */
+    template<typename Sample>
+    struct density_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type float_type;
+        typedef std::vector<std::pair<float_type, float_type> > histogram_type;
+        typedef std::vector<float_type> array_type;
+        // for boost::result_of
+        typedef iterator_range<typename histogram_type::iterator> result_type;
+
+        template<typename Args>
+        density_impl(Args const &args)
+            : cache_size(args[density_cache_size])
+            , cache(cache_size)
+            , num_bins(args[density_num_bins])
+            , samples_in_bin(num_bins + 2, 0.)
+            , bin_positions(num_bins + 2)
+            , histogram(
+                num_bins + 2
+              , std::make_pair(
+                    numeric::average(args[sample | Sample()],(std::size_t)1)
+                  , numeric::average(args[sample | Sample()],(std::size_t)1)
+                )
+              )
+            , is_dirty(true)
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            this->is_dirty = true;
+
+            std::size_t cnt = count(args);
+
+            // Fill up cache with cache_size first samples
+            if (cnt <= this->cache_size)
+            {
+                this->cache[cnt - 1] = args[sample];
+            }
+
+            // Once cache_size samples have been accumulated, create num_bins bins of same size between
+            // the minimum and maximum of the cached samples as well as an under- and and an overflow bin.
+            // Store their lower bounds (bin_positions) and fill the bins with the cached samples (samples_in_bin).
+            if (cnt == this->cache_size)
+            {
+                float_type minimum = numeric::average((min)(args), (std::size_t)1);
+                float_type maximum = numeric::average((max)(args), (std::size_t)1);
+                float_type bin_size = numeric::average(maximum - minimum, this->num_bins );
+
+                // determine bin positions (their lower bounds)
+                for (std::size_t i = 0; i < this->num_bins + 2; ++i)
+                {
+                    this->bin_positions[i] = minimum + (i - 1.) * bin_size;
+                }
+
+                for (typename array_type::const_iterator iter = this->cache.begin(); iter != this->cache.end(); ++iter)
+                {
+                    if (*iter < this->bin_positions[1])
+                    {
+                        ++(this->samples_in_bin[0]);
+                    }
+                    else if (*iter >= this->bin_positions[this->num_bins + 1])
+                    {
+                        ++(this->samples_in_bin[this->num_bins + 1]);
+                    }
+                    else
+                    {
+                        typename array_type::iterator it = std::upper_bound(
+                            this->bin_positions.begin()
+                          , this->bin_positions.end()
+                          , *iter
+                        );
+
+                        std::size_t d = std::distance(this->bin_positions.begin(), it);
+                        ++(this->samples_in_bin[d - 1]);
+                    }
+                }
+            }
+            // Add each subsequent sample to the correct bin
+            else if (cnt > this->cache_size)
+            {
+                if (args[sample] < this->bin_positions[1])
+                {
+                    ++(this->samples_in_bin[0]);
+                }
+                else if (args[sample] >= this->bin_positions[this->num_bins + 1])
+                {
+                    ++(this->samples_in_bin[this->num_bins + 1]);
+                }
+                else
+                {
+                    typename array_type::iterator it = std::upper_bound(
+                        this->bin_positions.begin()
+                      , this->bin_positions.end()
+                      , args[sample]
+                    );
+
+                    std::size_t d = std::distance(this->bin_positions.begin(), it);
+                    ++(this->samples_in_bin[d - 1]);
+                }
+            }
+        }
+
+        /**
+            @pre The number of samples must meet or exceed the cache size
+        */
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            if (this->is_dirty)
+            {
+                this->is_dirty = false;
+
+                // creates a vector of std::pair where each pair i holds
+                // the values bin_positions[i] (x-axis of histogram) and
+                // samples_in_bin[i] / cnt (y-axis of histogram).
+
+                for (std::size_t i = 0; i < this->num_bins + 2; ++i)
+                {
+                    this->histogram[i] = std::make_pair(this->bin_positions[i], numeric::average(this->samples_in_bin[i], count(args)));
+                }
+            }
+            // returns a range of pairs
+            return make_iterator_range(this->histogram);
+        }
+
+    private:
+        std::size_t            cache_size;      // number of cached samples
+        array_type             cache;           // cache to store the first cache_size samples
+        std::size_t            num_bins;        // number of bins
+        array_type             samples_in_bin;  // number of samples in each bin
+        array_type             bin_positions;   // lower bounds of bins
+        mutable histogram_type histogram;       // histogram
+        mutable bool is_dirty;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::density
+//
+namespace tag
+{
+    struct density
+      : depends_on<count, min, max>
+      , density_cache_size
+      , density_num_bins
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::density_impl<mpl::_1> impl;
+
+        #ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
+        /// tag::density::cache_size named parameter
+        /// tag::density::num_bins named parameter
+        static boost::parameter::keyword<density_cache_size> const cache_size;
+        static boost::parameter::keyword<density_num_bins> const num_bins;
+        #endif
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::density
+//
+namespace extract
+{
+    extractor<tag::density> const density = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(density)
+}
+
+using extract::density;
+
+// So that density can be automatically substituted
+// with weighted_density when the weight parameter is non-void.
+template<>
+struct as_weighted_feature<tag::density>
+{
+    typedef tag::weighted_density type;
+};
+
+template<>
+struct feature_of<tag::weighted_density>
+  : feature_of<tag::density>
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/error_of.hpp b/boost/accumulators/statistics/error_of.hpp
new file mode 100644
index 0000000..a29da02
--- /dev/null
+++ b/boost/accumulators/statistics/error_of.hpp
@@ -0,0 +1,99 @@
+///////////////////////////////////////////////////////////////////////////////
+// error_of.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_ERROR_OF_HPP_EAN_29_11_2005
+#define BOOST_ACCUMULATORS_STATISTICS_ERROR_OF_HPP_EAN_29_11_2005
+
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    /// INTERNAL ONLY
+    ///
+    template<typename Feature>
+    struct this_feature_has_no_error_calculation
+      : mpl::false_
+    {
+    };
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // error_of_impl
+    /// INTERNAL ONLY
+    ///
+    template<typename Sample, typename Feature>
+    struct error_of_impl
+      : accumulator_base
+    {
+        // TODO: specialize this on the specific features that have errors we're
+        // interested in.
+        BOOST_MPL_ASSERT((this_feature_has_no_error_calculation<Feature>));
+
+        // for boost::result_of
+        typedef int result_type;
+
+        error_of_impl(dont_care)
+        {
+        }
+
+        result_type result(dont_care) const
+        {
+            return 0;
+        }
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::error_of
+//
+namespace tag
+{
+    template<typename Feature>
+    struct error_of
+      : depends_on<Feature>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::error_of_impl<mpl::_1, Feature> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::error_of
+//
+namespace extract
+{
+    BOOST_ACCUMULATORS_DEFINE_EXTRACTOR(tag, error_of, (typename))
+}
+
+using extract::error_of;
+
+// make tag::error_of<tag::feature(modifier)> work
+template<typename Feature>
+struct as_feature<tag::error_of<Feature> >
+{
+    typedef tag::error_of<typename as_feature<Feature>::type> type;
+};
+
+// make error_of<tag::mean> work with non-void weights (should become
+// error_of<tag::weighted_mean>
+template<typename Feature>
+struct as_weighted_feature<tag::error_of<Feature> >
+{
+    typedef tag::error_of<typename as_weighted_feature<Feature>::type> type;
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/error_of_mean.hpp b/boost/accumulators/statistics/error_of_mean.hpp
new file mode 100644
index 0000000..9451d40
--- /dev/null
+++ b/boost/accumulators/statistics/error_of_mean.hpp
@@ -0,0 +1,73 @@
+///////////////////////////////////////////////////////////////////////////////
+// error_of.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_ERROR_OF_MEAN_HPP_EAN_27_03_2006
+#define BOOST_ACCUMULATORS_STATISTICS_ERROR_OF_MEAN_HPP_EAN_27_03_2006
+
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/error_of.hpp>
+#include <boost/accumulators/statistics/variance.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // error_of_mean_impl
+    template<typename Sample, typename Variance>
+    struct error_of_mean_impl
+      : accumulator_base
+    {
+        // for boost::result_of
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type result_type;
+
+        error_of_mean_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            using namespace std;
+            extractor<Variance> const variance = {};
+            return sqrt(numeric::average(variance(args), count(args) - 1));
+        }
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::error_of
+//
+namespace tag
+{
+    template<>
+    struct error_of<mean>
+      : depends_on<lazy_variance, count>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::error_of_mean_impl<mpl::_1, lazy_variance> impl;
+    };
+
+    template<>
+    struct error_of<immediate_mean>
+      : depends_on<variance, count>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::error_of_mean_impl<mpl::_1, variance> impl;
+    };
+}
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/extended_p_square.hpp b/boost/accumulators/statistics/extended_p_square.hpp
new file mode 100644
index 0000000..e8d4c04
--- /dev/null
+++ b/boost/accumulators/statistics/extended_p_square.hpp
@@ -0,0 +1,293 @@
+///////////////////////////////////////////////////////////////////////////////
+// extended_p_square.hpp
+//
+//  Copyright 2005 Daniel Egloff. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_EXTENDED_SINGLE_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_EXTENDED_SINGLE_HPP_DE_01_01_2006
+
+#include <vector>
+#include <functional>
+#include <boost/range/begin.hpp>
+#include <boost/range/end.hpp>
+#include <boost/range/iterator_range.hpp>
+#include <boost/iterator/transform_iterator.hpp>
+#include <boost/iterator/counting_iterator.hpp>
+#include <boost/iterator/permutation_iterator.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/times2_iterator.hpp>
+
+namespace boost { namespace accumulators
+{
+///////////////////////////////////////////////////////////////////////////////
+// probabilities named parameter
+//
+BOOST_PARAMETER_NESTED_KEYWORD(tag, extended_p_square_probabilities, probabilities)
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // extended_p_square_impl
+    //  multiple quantile estimation
+    /**
+        @brief Multiple quantile estimation with the extended \f$P^2\f$ algorithm
+
+        Extended \f$P^2\f$ algorithm for estimation of several quantiles without storing samples.
+        Assume that \f$m\f$ quantiles \f$\xi_{p_1}, \ldots, \xi_{p_m}\f$ are to be estimated.
+        Instead of storing the whole sample cumulative distribution, the algorithm maintains only
+        \f$m+2\f$ principal markers and \f$m+1\f$ middle markers, whose positions are updated
+        with each sample and whose heights are adjusted (if necessary) using a piecewise-parablic
+        formula. The heights of these central markers are the current estimates of the quantiles
+        and returned as an iterator range.
+
+        For further details, see
+
+        K. E. E. Raatikainen, Simultaneous estimation of several quantiles, Simulation, Volume 49,
+        Number 4 (October), 1986, p. 159-164.
+
+        The extended \f$ P^2 \f$ algorithm generalizess the \f$ P^2 \f$ algorithm of
+
+        R. Jain and I. Chlamtac, The P^2 algorithmus for dynamic calculation of quantiles and
+        histograms without storing observations, Communications of the ACM,
+        Volume 28 (October), Number 10, 1985, p. 1076-1085.
+
+        @param extended_p_square_probabilities A vector of quantile probabilities.
+    */
+    template<typename Sample>
+    struct extended_p_square_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type float_type;
+        typedef std::vector<float_type> array_type;
+        // for boost::result_of
+        typedef iterator_range<
+            detail::lvalue_index_iterator<
+                permutation_iterator<
+                    typename array_type::const_iterator
+                  , detail::times2_iterator
+                >
+            >
+        > result_type;
+
+        template<typename Args>
+        extended_p_square_impl(Args const &args)
+          : probabilities(
+                boost::begin(args[extended_p_square_probabilities])
+              , boost::end(args[extended_p_square_probabilities])
+            )
+          , heights(2 * probabilities.size() + 3)
+          , actual_positions(heights.size())
+          , desired_positions(heights.size())
+          , positions_increments(heights.size())
+        {
+            std::size_t num_quantiles = this->probabilities.size();
+            std::size_t num_markers = this->heights.size();
+
+            for(std::size_t i = 0; i < num_markers; ++i)
+            {
+                this->actual_positions[i] = i + 1;
+            }
+
+            this->positions_increments[0] = 0.;
+            this->positions_increments[num_markers - 1] = 1.;
+
+            for(std::size_t i = 0; i < num_quantiles; ++i)
+            {
+                this->positions_increments[2 * i + 2] = probabilities[i];
+            }
+
+            for(std::size_t i = 0; i <= num_quantiles; ++i)
+            {
+                this->positions_increments[2 * i + 1] =
+                    0.5 * (this->positions_increments[2 * i] + this->positions_increments[2 * i + 2]);
+            }
+
+            for(std::size_t i = 0; i < num_markers; ++i)
+            {
+                this->desired_positions[i] = 1. + 2. * (num_quantiles + 1.) * this->positions_increments[i];
+            }
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            std::size_t cnt = count(args);
+
+            // m+2 principal markers and m+1 middle markers
+            std::size_t num_markers = 2 * this->probabilities.size() + 3;
+
+            // first accumulate num_markers samples
+            if(cnt <= num_markers)
+            {
+                this->heights[cnt - 1] = args[sample];
+
+                // complete the initialization of heights by sorting
+                if(cnt == num_markers)
+                {
+                    std::sort(this->heights.begin(), this->heights.end());
+                }
+            }
+            else
+            {
+                std::size_t sample_cell = 1;
+
+                // find cell k = sample_cell such that heights[k-1] <= sample < heights[k]
+                if(args[sample] < this->heights[0])
+                {
+                    this->heights[0] = args[sample];
+                    sample_cell = 1;
+                }
+                else if(args[sample] >= this->heights[num_markers - 1])
+                {
+                    this->heights[num_markers - 1] = args[sample];
+                    sample_cell = num_markers - 1;
+                }
+                else
+                {
+                    typedef typename array_type::iterator iterator;
+                    iterator it = std::upper_bound(
+                        this->heights.begin()
+                      , this->heights.end()
+                      , args[sample]
+                    );
+
+                    sample_cell = std::distance(this->heights.begin(), it);
+                }
+
+                // update actual positions of all markers above sample_cell index
+                for(std::size_t i = sample_cell; i < num_markers; ++i)
+                {
+                    ++this->actual_positions[i];
+                }
+
+                // update desired positions of all markers
+                for(std::size_t i = 0; i < num_markers; ++i)
+                {
+                    this->desired_positions[i] += this->positions_increments[i];
+                }
+
+                // adjust heights and actual positions of markers 1 to num_markers-2 if necessary
+                for(std::size_t i = 1; i <= num_markers - 2; ++i)
+                {
+                    // offset to desired position
+                    float_type d = this->desired_positions[i] - this->actual_positions[i];
+
+                    // offset to next position
+                    float_type dp = this->actual_positions[i+1] - this->actual_positions[i];
+
+                    // offset to previous position
+                    float_type dm = this->actual_positions[i-1] - this->actual_positions[i];
+
+                    // height ds
+                    float_type hp = (this->heights[i+1] - this->heights[i]) / dp;
+                    float_type hm = (this->heights[i-1] - this->heights[i]) / dm;
+
+                    if((d >= 1 && dp > 1) || (d <= -1 && dm < -1))
+                    {
+                        short sign_d = static_cast<short>(d / std::abs(d));
+
+                        float_type h = this->heights[i] + sign_d / (dp - dm) * ((sign_d - dm)*hp
+                                     + (dp - sign_d) * hm);
+
+                        // try adjusting heights[i] using p-squared formula
+                        if(this->heights[i - 1] < h && h < this->heights[i + 1])
+                        {
+                            this->heights[i] = h;
+                        }
+                        else
+                        {
+                            // use linear formula
+                            if(d > 0)
+                            {
+                                this->heights[i] += hp;
+                            }
+                            if(d < 0)
+                            {
+                                this->heights[i] -= hm;
+                            }
+                        }
+                        this->actual_positions[i] += sign_d;
+                    }
+                }
+            }
+        }
+
+        result_type result(dont_care) const
+        {
+            // for i in [1,probabilities.size()], return heights[i * 2]
+            detail::times2_iterator idx_begin = detail::make_times2_iterator(1);
+            detail::times2_iterator idx_end = detail::make_times2_iterator(this->probabilities.size() + 1);
+
+            return result_type(
+                make_permutation_iterator(this->heights.begin(), idx_begin)
+              , make_permutation_iterator(this->heights.begin(), idx_end)
+            );
+        }
+
+    private:
+        array_type probabilities;         // the quantile probabilities
+        array_type heights;               // q_i
+        array_type actual_positions;      // n_i
+        array_type desired_positions;     // d_i
+        array_type positions_increments;  // f_i
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::extended_p_square
+//
+namespace tag
+{
+    struct extended_p_square
+      : depends_on<count>
+      , extended_p_square_probabilities
+    {
+        typedef accumulators::impl::extended_p_square_impl<mpl::_1> impl;
+
+        #ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
+        /// tag::extended_p_square::probabilities named paramter
+        static boost::parameter::keyword<tag::probabilities> const probabilities;
+        #endif
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::extended_p_square
+//
+namespace extract
+{
+    extractor<tag::extended_p_square> const extended_p_square = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(extended_p_square)
+}
+
+using extract::extended_p_square;
+
+// So that extended_p_square can be automatically substituted with
+// weighted_extended_p_square when the weight parameter is non-void
+template<>
+struct as_weighted_feature<tag::extended_p_square>
+{
+    typedef tag::weighted_extended_p_square type;
+};
+
+template<>
+struct feature_of<tag::weighted_extended_p_square>
+  : feature_of<tag::extended_p_square>
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/extended_p_square_quantile.hpp b/boost/accumulators/statistics/extended_p_square_quantile.hpp
new file mode 100644
index 0000000..b6c008d
--- /dev/null
+++ b/boost/accumulators/statistics/extended_p_square_quantile.hpp
@@ -0,0 +1,319 @@
+///////////////////////////////////////////////////////////////////////////////
+// extended_p_square_quantile.hpp
+//
+//  Copyright 2005 Daniel Egloff. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_EXTENDED_SINGLE_QUANTILE_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_EXTENDED_SINGLE_QUANTILE_HPP_DE_01_01_2006
+
+#include <vector>
+#include <functional>
+#include <boost/range/begin.hpp>
+#include <boost/range/end.hpp>
+#include <boost/range/iterator_range.hpp>
+#include <boost/iterator/transform_iterator.hpp>
+#include <boost/iterator/counting_iterator.hpp>
+#include <boost/iterator/permutation_iterator.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/parameters/quantile_probability.hpp>
+#include <boost/accumulators/statistics/extended_p_square.hpp>
+#include <boost/accumulators/statistics/weighted_extended_p_square.hpp>
+#include <boost/accumulators/statistics/times2_iterator.hpp>
+
+#ifdef _MSC_VER
+# pragma warning(push)
+# pragma warning(disable: 4127) // conditional expression is constant
+#endif
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // extended_p_square_quantile_impl
+    //  single quantile estimation
+    /**
+        @brief Quantile estimation using the extended \f$P^2\f$ algorithm for weighted and unweighted samples
+
+        Uses the quantile estimates calculated by the extended \f$P^2\f$ algorithm to compute
+        intermediate quantile estimates by means of quadratic interpolation.
+
+        @param quantile_probability The probability of the quantile to be estimated.
+    */
+    template<typename Sample, typename Impl1, typename Impl2> // Impl1: weighted/unweighted // Impl2: linear/quadratic
+    struct extended_p_square_quantile_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type float_type;
+        typedef std::vector<float_type> array_type;
+        typedef iterator_range<
+            detail::lvalue_index_iterator<
+                permutation_iterator<
+                    typename array_type::const_iterator
+                  , detail::times2_iterator
+                >
+            >
+        > range_type;
+        // for boost::result_of
+        typedef float_type result_type;
+
+        template<typename Args>
+        extended_p_square_quantile_impl(Args const &args)
+          : probabilities(
+                boost::begin(args[extended_p_square_probabilities])
+              , boost::end(args[extended_p_square_probabilities])
+            )
+        {
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            typedef
+                typename mpl::if_<
+                    is_same<Impl1, weighted>
+                  , tag::weighted_extended_p_square
+                  , tag::extended_p_square
+                >::type
+            extended_p_square_tag;
+
+            extractor<extended_p_square_tag> const some_extended_p_square = {};
+
+            array_type heights(some_extended_p_square(args).size());
+            std::copy(some_extended_p_square(args).begin(), some_extended_p_square(args).end(), heights.begin());
+
+            this->probability = args[quantile_probability];
+
+            typename array_type::const_iterator iter_probs = std::lower_bound(this->probabilities.begin(), this->probabilities.end(), this->probability);
+            std::size_t dist = std::distance(this->probabilities.begin(), iter_probs);
+            typename array_type::const_iterator iter_heights = heights.begin() + dist;
+
+            // If this->probability is not in a valid range return NaN or throw exception
+            if (this->probability < *this->probabilities.begin() || this->probability > *(this->probabilities.end() - 1))
+            {
+                if (std::numeric_limits<result_type>::has_quiet_NaN)
+                {
+                    return std::numeric_limits<result_type>::quiet_NaN();
+                }
+                else
+                {
+                    std::ostringstream msg;
+                    msg << "probability = " << this->probability << " is not in valid range (";
+                    msg << *this->probabilities.begin() << ", " << *(this->probabilities.end() - 1) << ")";
+                    boost::throw_exception(std::runtime_error(msg.str()));
+                    return Sample(0);
+                }
+
+            }
+
+            if (*iter_probs == this->probability)
+            {
+                return heights[dist];
+            }
+            else
+            {
+                result_type res;
+
+                if (is_same<Impl2, linear>::value)
+                {
+                    /////////////////////////////////////////////////////////////////////////////////
+                    // LINEAR INTERPOLATION
+                    //
+                    float_type p1 = *iter_probs;
+                    float_type p0 = *(iter_probs - 1);
+                    float_type h1 = *iter_heights;
+                    float_type h0 = *(iter_heights - 1);
+
+                    float_type a = numeric::average(h1 - h0, p1 - p0);
+                    float_type b = h1 - p1 * a;
+
+                    res = a * this->probability + b;
+                }
+                else
+                {
+                    /////////////////////////////////////////////////////////////////////////////////
+                    // QUADRATIC INTERPOLATION
+                    //
+                    float_type p0, p1, p2;
+                    float_type h0, h1, h2;
+
+                    if ( (dist == 1 || *iter_probs - this->probability <= this->probability - *(iter_probs - 1) ) && dist != this->probabilities.size() - 1 )
+                    {
+                        p0 = *(iter_probs - 1);
+                        p1 = *iter_probs;
+                        p2 = *(iter_probs + 1);
+                        h0 = *(iter_heights - 1);
+                        h1 = *iter_heights;
+                        h2 = *(iter_heights + 1);
+                    }
+                    else
+                    {
+                        p0 = *(iter_probs - 2);
+                        p1 = *(iter_probs - 1);
+                        p2 = *iter_probs;
+                        h0 = *(iter_heights - 2);
+                        h1 = *(iter_heights - 1);
+                        h2 = *iter_heights;
+                    }
+
+                    float_type hp21 = numeric::average(h2 - h1, p2 - p1);
+                    float_type hp10 = numeric::average(h1 - h0, p1 - p0);
+                    float_type p21  = numeric::average(p2 * p2 - p1 * p1, p2 - p1);
+                    float_type p10  = numeric::average(p1 * p1 - p0 * p0, p1 - p0);
+
+                    float_type a = numeric::average(hp21 - hp10, p21 - p10);
+                    float_type b = hp21 - a * p21;
+                    float_type c = h2 - a * p2 * p2 - b * p2;
+
+                    res = a * this->probability * this-> probability + b * this->probability + c;
+                }
+
+                return res;
+            }
+
+        }
+    private:
+
+        array_type probabilities;
+        mutable float_type probability;
+
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::extended_p_square_quantile
+//
+namespace tag
+{
+    struct extended_p_square_quantile
+      : depends_on<extended_p_square>
+    {
+        typedef accumulators::impl::extended_p_square_quantile_impl<mpl::_1, unweighted, linear> impl;
+    };
+    struct extended_p_square_quantile_quadratic
+      : depends_on<extended_p_square>
+    {
+        typedef accumulators::impl::extended_p_square_quantile_impl<mpl::_1, unweighted, quadratic> impl;
+    };
+    struct weighted_extended_p_square_quantile
+      : depends_on<weighted_extended_p_square>
+    {
+        typedef accumulators::impl::extended_p_square_quantile_impl<mpl::_1, weighted, linear> impl;
+    };
+    struct weighted_extended_p_square_quantile_quadratic
+      : depends_on<weighted_extended_p_square>
+    {
+        typedef accumulators::impl::extended_p_square_quantile_impl<mpl::_1, weighted, quadratic> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::extended_p_square_quantile
+// extract::weighted_extended_p_square_quantile
+//
+namespace extract
+{
+    extractor<tag::extended_p_square_quantile> const extended_p_square_quantile = {};
+    extractor<tag::extended_p_square_quantile_quadratic> const extended_p_square_quantile_quadratic = {};
+    extractor<tag::weighted_extended_p_square_quantile> const weighted_extended_p_square_quantile = {};
+    extractor<tag::weighted_extended_p_square_quantile_quadratic> const weighted_extended_p_square_quantile_quadratic = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(extended_p_square_quantile)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(extended_p_square_quantile_quadratic)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_extended_p_square_quantile)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_extended_p_square_quantile_quadratic)
+}
+
+using extract::extended_p_square_quantile;
+using extract::extended_p_square_quantile_quadratic;
+using extract::weighted_extended_p_square_quantile;
+using extract::weighted_extended_p_square_quantile_quadratic;
+
+// extended_p_square_quantile(linear) -> extended_p_square_quantile
+template<>
+struct as_feature<tag::extended_p_square_quantile(linear)>
+{
+    typedef tag::extended_p_square_quantile type;
+};
+
+// extended_p_square_quantile(quadratic) -> extended_p_square_quantile_quadratic
+template<>
+struct as_feature<tag::extended_p_square_quantile(quadratic)>
+{
+    typedef tag::extended_p_square_quantile_quadratic type;
+};
+
+// weighted_extended_p_square_quantile(linear) -> weighted_extended_p_square_quantile
+template<>
+struct as_feature<tag::weighted_extended_p_square_quantile(linear)>
+{
+    typedef tag::weighted_extended_p_square_quantile type;
+};
+
+// weighted_extended_p_square_quantile(quadratic) -> weighted_extended_p_square_quantile_quadratic
+template<>
+struct as_feature<tag::weighted_extended_p_square_quantile(quadratic)>
+{
+    typedef tag::weighted_extended_p_square_quantile_quadratic type;
+};
+
+// for the purposes of feature-based dependency resolution,
+// extended_p_square_quantile and weighted_extended_p_square_quantile
+// provide the same feature as quantile
+template<>
+struct feature_of<tag::extended_p_square_quantile>
+  : feature_of<tag::quantile>
+{
+};
+template<>
+struct feature_of<tag::extended_p_square_quantile_quadratic>
+  : feature_of<tag::quantile>
+{
+};
+// So that extended_p_square_quantile can be automatically substituted with
+// weighted_extended_p_square_quantile when the weight parameter is non-void
+template<>
+struct as_weighted_feature<tag::extended_p_square_quantile>
+{
+    typedef tag::weighted_extended_p_square_quantile type;
+};
+
+template<>
+struct feature_of<tag::weighted_extended_p_square_quantile>
+  : feature_of<tag::extended_p_square_quantile>
+{
+};
+
+// So that extended_p_square_quantile_quadratic can be automatically substituted with
+// weighted_extended_p_square_quantile_quadratic when the weight parameter is non-void
+template<>
+struct as_weighted_feature<tag::extended_p_square_quantile_quadratic>
+{
+    typedef tag::weighted_extended_p_square_quantile_quadratic type;
+};
+template<>
+struct feature_of<tag::weighted_extended_p_square_quantile_quadratic>
+  : feature_of<tag::extended_p_square_quantile_quadratic>
+{
+};
+
+}} // namespace boost::accumulators
+
+#ifdef _MSC_VER
+# pragma warning(pop)
+#endif
+
+#endif
diff --git a/boost/accumulators/statistics/kurtosis.hpp b/boost/accumulators/statistics/kurtosis.hpp
new file mode 100644
index 0000000..4c5c23d
--- /dev/null
+++ b/boost/accumulators/statistics/kurtosis.hpp
@@ -0,0 +1,112 @@
+///////////////////////////////////////////////////////////////////////////////
+// kurtosis.hpp
+//
+//  Copyright 2006 Olivier Gygi, Daniel Egloff. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_KURTOSIS_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_KURTOSIS_HPP_EAN_28_10_2005
+
+#include <limits>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics/mean.hpp>
+#include <boost/accumulators/statistics/moment.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // kurtosis_impl
+    /**
+        @brief Kurtosis estimation
+
+        The kurtosis of a sample distribution is defined as the ratio of the 4th central moment and the square of the 2nd central
+        moment (the variance) of the samples, minus 3. The term \f$ -3 \f$ is added in order to ensure that the normal distribution
+        has zero kurtosis. The kurtosis can also be expressed by the simple moments:
+
+        \f[
+            \hat{g}_2 =
+                \frac
+                {\widehat{m}_n^{(4)}-4\widehat{m}_n^{(3)}\hat{\mu}_n+6\widehat{m}_n^{(2)}\hat{\mu}_n^2-3\hat{\mu}_n^4}
+                {\left(\widehat{m}_n^{(2)} - \hat{\mu}_n^{2}\right)^2} - 3,
+        \f]
+
+        where \f$ \widehat{m}_n^{(i)} \f$ are the \f$ i \f$-th moment and \f$ \hat{\mu}_n \f$ the mean (first moment) of the
+        \f$ n \f$ samples.
+    */
+    template<typename Sample>
+    struct kurtosis_impl
+      : accumulator_base
+    {
+        // for boost::result_of
+        typedef typename numeric::functional::average<Sample, Sample>::result_type result_type;
+
+        kurtosis_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            return numeric::average(
+                        accumulators::moment<4>(args)
+                        - 4. * accumulators::moment<3>(args) * mean(args)
+                        + 6. * accumulators::moment<2>(args) * mean(args) * mean(args)
+                        - 3. * mean(args) * mean(args) * mean(args) * mean(args)
+                      , ( accumulators::moment<2>(args) - mean(args) * mean(args) )
+                        * ( accumulators::moment<2>(args) - mean(args) * mean(args) )
+                    ) - 3.;
+        }
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::kurtosis
+//
+namespace tag
+{
+    struct kurtosis
+      : depends_on<mean, moment<2>, moment<3>, moment<4> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::kurtosis_impl<mpl::_1> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::kurtosis
+//
+namespace extract
+{
+    extractor<tag::kurtosis> const kurtosis = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(kurtosis)
+}
+
+using extract::kurtosis;
+
+// So that kurtosis can be automatically substituted with
+// weighted_kurtosis when the weight parameter is non-void
+template<>
+struct as_weighted_feature<tag::kurtosis>
+{
+    typedef tag::weighted_kurtosis type;
+};
+
+template<>
+struct feature_of<tag::weighted_kurtosis>
+  : feature_of<tag::kurtosis>
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/max.hpp b/boost/accumulators/statistics/max.hpp
new file mode 100644
index 0000000..820f659
--- /dev/null
+++ b/boost/accumulators/statistics/max.hpp
@@ -0,0 +1,85 @@
+///////////////////////////////////////////////////////////////////////////////
+// max.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_MAX_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_MAX_HPP_EAN_28_10_2005
+
+#include <limits>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // max_impl
+    template<typename Sample>
+    struct max_impl
+      : accumulator_base
+    {
+        // for boost::result_of
+        typedef Sample result_type;
+
+        template<typename Args>
+        max_impl(Args const &args)
+          : max_(numeric::as_min(args[sample | Sample()]))
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            numeric::max_assign(this->max_, args[sample]);
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->max_;
+        }
+
+    private:
+        Sample max_;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::max
+//
+namespace tag
+{
+    struct max
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::max_impl<mpl::_1> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::max
+//
+namespace extract
+{
+    extractor<tag::max> const max = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(max)
+}
+
+using extract::max;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/mean.hpp b/boost/accumulators/statistics/mean.hpp
new file mode 100644
index 0000000..0b3ba5e
--- /dev/null
+++ b/boost/accumulators/statistics/mean.hpp
@@ -0,0 +1,298 @@
+///////////////////////////////////////////////////////////////////////////////
+// mean.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_MEAN_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_MEAN_HPP_EAN_28_10_2005
+
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/sum.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // mean_impl
+    //      lazy, by default
+    template<typename Sample, typename SumFeature>
+    struct mean_impl
+      : accumulator_base
+    {
+        // for boost::result_of
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type result_type;
+
+        mean_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            extractor<SumFeature> sum;
+            return numeric::average(sum(args), count(args));
+        }
+    };
+
+    template<typename Sample, typename Tag>
+    struct immediate_mean_impl
+      : accumulator_base
+    {
+        // for boost::result_of
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type result_type;
+
+        template<typename Args>
+        immediate_mean_impl(Args const &args)
+          : mean(numeric::average(args[sample | Sample()], numeric::one<std::size_t>::value))
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            std::size_t cnt = count(args);
+            this->mean = numeric::average(
+                (this->mean * (cnt - 1)) + args[parameter::keyword<Tag>::get()]
+              , cnt
+            );
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->mean;
+        }
+
+    private:
+        result_type mean;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::mean
+// tag::immediate_mean
+// tag::mean_of_weights
+// tag::immediate_mean_of_weights
+// tag::mean_of_variates
+// tag::immediate_mean_of_variates
+//
+namespace tag
+{
+    struct mean
+      : depends_on<count, sum>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::mean_impl<mpl::_1, sum> impl;
+    };
+    struct immediate_mean
+      : depends_on<count>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::immediate_mean_impl<mpl::_1, tag::sample> impl;
+    };
+    struct mean_of_weights
+      : depends_on<count, sum_of_weights>
+    {
+        typedef mpl::true_ is_weight_accumulator;
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::mean_impl<mpl::_2, sum_of_weights> impl;
+    };
+    struct immediate_mean_of_weights
+      : depends_on<count>
+    {
+        typedef mpl::true_ is_weight_accumulator;
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::immediate_mean_impl<mpl::_2, tag::weight> impl;
+    };
+    template<typename VariateType, typename VariateTag>
+    struct mean_of_variates
+      : depends_on<count, sum_of_variates<VariateType, VariateTag> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef mpl::always<accumulators::impl::mean_impl<VariateType, sum_of_variates<VariateType, VariateTag> > > impl;
+    };
+    template<typename VariateType, typename VariateTag>
+    struct immediate_mean_of_variates
+      : depends_on<count>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef mpl::always<accumulators::impl::immediate_mean_impl<VariateType, VariateTag> > impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::mean
+// extract::mean_of_weights
+// extract::mean_of_variates
+//
+namespace extract
+{
+    extractor<tag::mean> const mean = {};
+    extractor<tag::mean_of_weights> const mean_of_weights = {};
+    BOOST_ACCUMULATORS_DEFINE_EXTRACTOR(tag, mean_of_variates, (typename)(typename))
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(mean)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(mean_of_weights)
+}
+
+using extract::mean;
+using extract::mean_of_weights;
+using extract::mean_of_variates;
+
+// mean(lazy) -> mean
+template<>
+struct as_feature<tag::mean(lazy)>
+{
+    typedef tag::mean type;
+};
+
+// mean(immediate) -> immediate_mean
+template<>
+struct as_feature<tag::mean(immediate)>
+{
+    typedef tag::immediate_mean type;
+};
+
+// mean_of_weights(lazy) -> mean_of_weights
+template<>
+struct as_feature<tag::mean_of_weights(lazy)>
+{
+    typedef tag::mean_of_weights type;
+};
+
+// mean_of_weights(immediate) -> immediate_mean_of_weights
+template<>
+struct as_feature<tag::mean_of_weights(immediate)>
+{
+    typedef tag::immediate_mean_of_weights type;
+};
+
+// mean_of_variates<VariateType, VariateTag>(lazy) -> mean_of_variates<VariateType, VariateTag>
+template<typename VariateType, typename VariateTag>
+struct as_feature<tag::mean_of_variates<VariateType, VariateTag>(lazy)>
+{
+    typedef tag::mean_of_variates<VariateType, VariateTag> type;
+};
+
+// mean_of_variates<VariateType, VariateTag>(immediate) -> immediate_mean_of_variates<VariateType, VariateTag>
+template<typename VariateType, typename VariateTag>
+struct as_feature<tag::mean_of_variates<VariateType, VariateTag>(immediate)>
+{
+    typedef tag::immediate_mean_of_variates<VariateType, VariateTag> type;
+};
+
+// for the purposes of feature-based dependency resolution,
+// immediate_mean provides the same feature as mean
+template<>
+struct feature_of<tag::immediate_mean>
+  : feature_of<tag::mean>
+{
+};
+
+// for the purposes of feature-based dependency resolution,
+// immediate_mean provides the same feature as mean
+template<>
+struct feature_of<tag::immediate_mean_of_weights>
+  : feature_of<tag::mean_of_weights>
+{
+};
+
+// for the purposes of feature-based dependency resolution,
+// immediate_mean provides the same feature as mean
+template<typename VariateType, typename VariateTag>
+struct feature_of<tag::immediate_mean_of_variates<VariateType, VariateTag> >
+  : feature_of<tag::mean_of_variates<VariateType, VariateTag> >
+{
+};
+
+// So that mean can be automatically substituted with
+// weighted_mean when the weight parameter is non-void.
+template<>
+struct as_weighted_feature<tag::mean>
+{
+    typedef tag::weighted_mean type;
+};
+
+template<>
+struct feature_of<tag::weighted_mean>
+  : feature_of<tag::mean>
+{};
+
+// So that immediate_mean can be automatically substituted with
+// immediate_weighted_mean when the weight parameter is non-void.
+template<>
+struct as_weighted_feature<tag::immediate_mean>
+{
+    typedef tag::immediate_weighted_mean type;
+};
+
+template<>
+struct feature_of<tag::immediate_weighted_mean>
+  : feature_of<tag::immediate_mean>
+{};
+
+// So that mean_of_weights<> can be automatically substituted with
+// weighted_mean_of_variates<> when the weight parameter is non-void.
+template<typename VariateType, typename VariateTag>
+struct as_weighted_feature<tag::mean_of_variates<VariateType, VariateTag> >
+{
+    typedef tag::weighted_mean_of_variates<VariateType, VariateTag> type;
+};
+
+template<typename VariateType, typename VariateTag>
+struct feature_of<tag::weighted_mean_of_variates<VariateType, VariateTag> >
+  : feature_of<tag::mean_of_variates<VariateType, VariateTag> >
+{
+};
+
+// So that immediate_mean_of_weights<> can be automatically substituted with
+// immediate_weighted_mean_of_variates<> when the weight parameter is non-void.
+template<typename VariateType, typename VariateTag>
+struct as_weighted_feature<tag::immediate_mean_of_variates<VariateType, VariateTag> >
+{
+    typedef tag::immediate_weighted_mean_of_variates<VariateType, VariateTag> type;
+};
+
+template<typename VariateType, typename VariateTag>
+struct feature_of<tag::immediate_weighted_mean_of_variates<VariateType, VariateTag> >
+  : feature_of<tag::immediate_mean_of_variates<VariateType, VariateTag> >
+{
+};
+
+////////////////////////////////////////////////////////////////////////////
+//// droppable_accumulator<mean_impl>
+////  need to specialize droppable lazy mean to cache the result at the
+////  point the accumulator is dropped.
+///// INTERNAL ONLY
+/////
+//template<typename Sample, typename SumFeature>
+//struct droppable_accumulator<impl::mean_impl<Sample, SumFeature> >
+//  : droppable_accumulator_base<
+//        with_cached_result<impl::mean_impl<Sample, SumFeature> >
+//    >
+//{
+//    template<typename Args>
+//    droppable_accumulator(Args const &args)
+//      : droppable_accumulator::base(args)
+//    {
+//    }
+//};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/median.hpp b/boost/accumulators/statistics/median.hpp
new file mode 100644
index 0000000..13ebb28
--- /dev/null
+++ b/boost/accumulators/statistics/median.hpp
@@ -0,0 +1,301 @@
+///////////////////////////////////////////////////////////////////////////////
+// median.hpp
+//
+//  Copyright 2006 Eric Niebler, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_MEDIAN_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_MEDIAN_HPP_EAN_28_10_2005
+
+#include <boost/mpl/placeholders.hpp>
+#include <boost/range/iterator_range.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/p_square_quantile.hpp>
+#include <boost/accumulators/statistics/density.hpp>
+#include <boost/accumulators/statistics/p_square_cumulative_distribution.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // median_impl
+    //
+    /**
+        @brief Median estimation based on the \f$P^2\f$ quantile estimator
+
+        The \f$P^2\f$ algorithm is invoked with a quantile probability of 0.5.
+    */
+    template<typename Sample>
+    struct median_impl
+      : accumulator_base
+    {
+        // for boost::result_of
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type result_type;
+
+        median_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            return p_square_quantile_for_median(args);
+        }
+    };
+    ///////////////////////////////////////////////////////////////////////////////
+    // with_density_median_impl
+    //
+    /**
+        @brief Median estimation based on the density estimator
+
+        The algorithm determines the bin in which the \f$0.5*cnt\f$-th sample lies, \f$cnt\f$ being
+        the total number of samples. It returns the approximate horizontal position of this sample,
+        based on a linear interpolation inside the bin.
+    */
+    template<typename Sample>
+    struct with_density_median_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type float_type;
+        typedef std::vector<std::pair<float_type, float_type> > histogram_type;
+        typedef iterator_range<typename histogram_type::iterator> range_type;
+        // for boost::result_of
+        typedef float_type result_type;
+
+        template<typename Args>
+        with_density_median_impl(Args const &args)
+          : sum(numeric::average(args[sample | Sample()], (std::size_t)1))
+          , is_dirty(true)
+        {
+        }
+
+        void operator ()(dont_care)
+        {
+            this->is_dirty = true;
+        }
+
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            if (this->is_dirty)
+            {
+                this->is_dirty = false;
+
+                std::size_t cnt = count(args);
+                range_type histogram = density(args);
+                typename range_type::iterator it = histogram.begin();
+                while (this->sum < 0.5 * cnt)
+                {
+                    this->sum += it->second * cnt;
+                    ++it;
+                }
+                --it;
+                float_type over = numeric::average(this->sum - 0.5 * cnt, it->second * cnt);
+                this->median = it->first * over + (it + 1)->first * (1. - over);
+            }
+
+            return this->median;
+        }
+
+    private:
+        mutable float_type sum;
+        mutable bool is_dirty;
+        mutable float_type median;
+    };
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // with_p_square_cumulative_distribution_median_impl
+    //
+    /**
+        @brief Median estimation based on the \f$P^2\f$ cumulative distribution estimator
+
+        The algorithm determines the first (leftmost) bin with a height exceeding 0.5. It
+        returns the approximate horizontal position of where the cumulative distribution
+        equals 0.5, based on a linear interpolation inside the bin.
+    */
+    template<typename Sample>
+    struct with_p_square_cumulative_distribution_median_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type float_type;
+        typedef std::vector<std::pair<float_type, float_type> > histogram_type;
+        typedef iterator_range<typename histogram_type::iterator> range_type;
+        // for boost::result_of
+        typedef float_type result_type;
+
+        with_p_square_cumulative_distribution_median_impl(dont_care)
+          : is_dirty(true)
+        {
+        }
+
+        void operator ()(dont_care)
+        {
+            this->is_dirty = true;
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            if (this->is_dirty)
+            {
+                this->is_dirty = false;
+
+                range_type histogram = p_square_cumulative_distribution(args);
+                typename range_type::iterator it = histogram.begin();
+                while (it->second < 0.5)
+                {
+                    ++it;
+                }
+                float_type over = numeric::average(it->second - 0.5, it->second - (it - 1)->second);
+                this->median = it->first * over + (it + 1)->first * ( 1. - over );
+            }
+
+            return this->median;
+        }
+    private:
+
+        mutable bool is_dirty;
+        mutable float_type median;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::median
+// tag::with_densisty_median
+// tag::with_p_square_cumulative_distribution_median
+//
+namespace tag
+{
+    struct median
+      : depends_on<p_square_quantile_for_median>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::median_impl<mpl::_1> impl;
+    };
+    struct with_density_median
+      : depends_on<count, density>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::with_density_median_impl<mpl::_1> impl;
+    };
+    struct with_p_square_cumulative_distribution_median
+      : depends_on<p_square_cumulative_distribution>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::with_p_square_cumulative_distribution_median_impl<mpl::_1> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::median
+// extract::with_density_median
+// extract::with_p_square_cumulative_distribution_median
+//
+namespace extract
+{
+    extractor<tag::median> const median = {};
+    extractor<tag::with_density_median> const with_density_median = {};
+    extractor<tag::with_p_square_cumulative_distribution_median> const with_p_square_cumulative_distribution_median = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(median)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(with_density_median)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(with_p_square_cumulative_distribution_median)
+}
+
+using extract::median;
+using extract::with_density_median;
+using extract::with_p_square_cumulative_distribution_median;
+
+// median(with_p_square_quantile) -> median
+template<>
+struct as_feature<tag::median(with_p_square_quantile)>
+{
+    typedef tag::median type;
+};
+
+// median(with_density) -> with_density_median
+template<>
+struct as_feature<tag::median(with_density)>
+{
+    typedef tag::with_density_median type;
+};
+
+// median(with_p_square_cumulative_distribution) -> with_p_square_cumulative_distribution_median
+template<>
+struct as_feature<tag::median(with_p_square_cumulative_distribution)>
+{
+    typedef tag::with_p_square_cumulative_distribution_median type;
+};
+
+// for the purposes of feature-based dependency resolution,
+// with_density_median and with_p_square_cumulative_distribution_median
+// provide the same feature as median
+template<>
+struct feature_of<tag::with_density_median>
+  : feature_of<tag::median>
+{
+};
+
+template<>
+struct feature_of<tag::with_p_square_cumulative_distribution_median>
+  : feature_of<tag::median>
+{
+};
+
+// So that median can be automatically substituted with
+// weighted_median when the weight parameter is non-void.
+template<>
+struct as_weighted_feature<tag::median>
+{
+    typedef tag::weighted_median type;
+};
+
+template<>
+struct feature_of<tag::weighted_median>
+  : feature_of<tag::median>
+{
+};
+
+// So that with_density_median can be automatically substituted with
+// with_density_weighted_median when the weight parameter is non-void.
+template<>
+struct as_weighted_feature<tag::with_density_median>
+{
+    typedef tag::with_density_weighted_median type;
+};
+
+template<>
+struct feature_of<tag::with_density_weighted_median>
+  : feature_of<tag::with_density_median>
+{
+};
+
+// So that with_p_square_cumulative_distribution_median can be automatically substituted with
+// with_p_square_cumulative_distribution_weighted_median when the weight parameter is non-void.
+template<>
+struct as_weighted_feature<tag::with_p_square_cumulative_distribution_median>
+{
+    typedef tag::with_p_square_cumulative_distribution_weighted_median type;
+};
+
+template<>
+struct feature_of<tag::with_p_square_cumulative_distribution_weighted_median>
+  : feature_of<tag::with_p_square_cumulative_distribution_median>
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/min.hpp b/boost/accumulators/statistics/min.hpp
new file mode 100644
index 0000000..83943bd
--- /dev/null
+++ b/boost/accumulators/statistics/min.hpp
@@ -0,0 +1,85 @@
+///////////////////////////////////////////////////////////////////////////////
+// min.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_MIN_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_MIN_HPP_EAN_28_10_2005
+
+#include <limits>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // min_impl
+    template<typename Sample>
+    struct min_impl
+      : accumulator_base
+    {
+        // for boost::result_of
+        typedef Sample result_type;
+
+        template<typename Args>
+        min_impl(Args const &args)
+          : min_(numeric::as_max(args[sample | Sample()]))
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            numeric::min_assign(this->min_, args[sample]);
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->min_;
+        }
+
+    private:
+        Sample min_;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::min
+//
+namespace tag
+{
+    struct min
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::min_impl<mpl::_1> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::min
+//
+namespace extract
+{
+    extractor<tag::min> const min = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(min)
+}
+
+using extract::min;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/moment.hpp b/boost/accumulators/statistics/moment.hpp
new file mode 100644
index 0000000..2042173
--- /dev/null
+++ b/boost/accumulators/statistics/moment.hpp
@@ -0,0 +1,125 @@
+///////////////////////////////////////////////////////////////////////////////
+// moment.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_MOMENT_HPP_EAN_15_11_2005
+#define BOOST_ACCUMULATORS_STATISTICS_MOMENT_HPP_EAN_15_11_2005
+
+#include <boost/config/no_tr1/cmath.hpp>
+#include <boost/mpl/int.hpp>
+#include <boost/mpl/assert.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+
+namespace boost { namespace numeric
+{
+    /// INTERNAL ONLY
+    ///
+    template<typename T>
+    T const &pow(T const &x, mpl::int_<1>)
+    {
+        return x;
+    }
+
+    /// INTERNAL ONLY
+    ///
+    template<typename T, int N>
+    T pow(T const &x, mpl::int_<N>)
+    {
+        using namespace operators;
+        T y = numeric::pow(x, mpl::int_<N/2>());
+        T z = y * y;
+        return (N % 2) ? (z * x) : z;
+    }
+}}
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // moment_impl
+    template<typename N, typename Sample>
+    struct moment_impl
+      : accumulator_base // TODO: also depends_on sum of powers
+    {
+        BOOST_MPL_ASSERT_RELATION(N::value, >, 0);
+        // for boost::result_of
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type result_type;
+
+        template<typename Args>
+        moment_impl(Args const &args)
+          : sum(args[sample | Sample()])
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            this->sum += numeric::pow(args[sample], N());
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            return numeric::average(this->sum, count(args));
+        }
+
+    private:
+        Sample sum;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::moment
+//
+namespace tag
+{
+    template<int N>
+    struct moment
+      : depends_on<count>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::moment_impl<mpl::int_<N>, mpl::_1> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::moment
+//
+namespace extract
+{
+    BOOST_ACCUMULATORS_DEFINE_EXTRACTOR(tag, moment, (int))
+}
+
+using extract::moment;
+
+// So that moment<N> can be automatically substituted with
+// weighted_moment<N> when the weight parameter is non-void
+template<int N>
+struct as_weighted_feature<tag::moment<N> >
+{
+    typedef tag::weighted_moment<N> type;
+};
+
+template<int N>
+struct feature_of<tag::weighted_moment<N> >
+  : feature_of<tag::moment<N> >
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/p_square_cumulative_distribution.hpp b/boost/accumulators/statistics/p_square_cumulative_distribution.hpp
new file mode 100644
index 0000000..437469c
--- /dev/null
+++ b/boost/accumulators/statistics/p_square_cumulative_distribution.hpp
@@ -0,0 +1,260 @@
+///////////////////////////////////////////////////////////////////////////////
+// p_square_cumulative_distribution.hpp
+//
+//  Copyright 2005 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_P_SQUARE_CUMULATIVE_DISTRIBUTION_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_P_SQUARE_CUMULATIVE_DISTRIBUTION_HPP_DE_01_01_2006
+
+#include <vector>
+#include <functional>
+#include <boost/parameter/keyword.hpp>
+#include <boost/range.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+
+namespace boost { namespace accumulators
+{
+///////////////////////////////////////////////////////////////////////////////
+// num_cells named parameter
+//
+BOOST_PARAMETER_NESTED_KEYWORD(tag, p_square_cumulative_distribution_num_cells, num_cells)
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // p_square_cumulative_distribution_impl
+    //  cumulative_distribution calculation (as histogram)
+    /**
+        @brief Histogram calculation of the cumulative distribution with the \f$P^2\f$ algorithm
+
+        A histogram of the sample cumulative distribution is computed dynamically without storing samples
+        based on the \f$ P^2 \f$ algorithm. The returned histogram has a specifiable amount (num_cells)
+        equiprobable (and not equal-sized) cells.
+
+        For further details, see
+
+        R. Jain and I. Chlamtac, The P^2 algorithmus for dynamic calculation of quantiles and
+        histograms without storing observations, Communications of the ACM,
+        Volume 28 (October), Number 10, 1985, p. 1076-1085.
+
+        @param p_square_cumulative_distribution_num_cells.
+    */
+    template<typename Sample>
+    struct p_square_cumulative_distribution_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type float_type;
+        typedef std::vector<float_type> array_type;
+        typedef std::vector<std::pair<float_type, float_type> > histogram_type;
+        // for boost::result_of
+        typedef iterator_range<typename histogram_type::iterator> result_type;
+
+        template<typename Args>
+        p_square_cumulative_distribution_impl(Args const &args)
+          : num_cells(args[p_square_cumulative_distribution_num_cells])
+          , heights(num_cells + 1)
+          , actual_positions(num_cells + 1)
+          , desired_positions(num_cells + 1)
+          , positions_increments(num_cells + 1)
+          , histogram(num_cells + 1)
+          , is_dirty(true)
+        {
+            std::size_t b = this->num_cells;
+
+            for (std::size_t i = 0; i < b + 1; ++i)
+            {
+                this->actual_positions[i] = i + 1.;
+                this->desired_positions[i] = i + 1.;
+                this->positions_increments[i] = numeric::average(i, b);
+            }
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            this->is_dirty = true;
+
+            std::size_t cnt = count(args);
+            std::size_t sample_cell = 1; // k
+            std::size_t b = this->num_cells;
+
+            // accumulate num_cells + 1 first samples
+            if (cnt <= b + 1)
+            {
+                this->heights[cnt - 1] = args[sample];
+
+                // complete the initialization of heights by sorting
+                if (cnt == b + 1)
+                {
+                    std::sort(this->heights.begin(), this->heights.end());
+                }
+            }
+            else
+            {
+                // find cell k such that heights[k-1] <= args[sample] < heights[k] and adjust extreme values
+                if (args[sample] < this->heights[0])
+                {
+                    this->heights[0] = args[sample];
+                    sample_cell = 1;
+                }
+                else if (this->heights[b] <= args[sample])
+                {
+                    this->heights[b] = args[sample];
+                    sample_cell = b;
+                }
+                else
+                {
+                    typename array_type::iterator it;
+                    it = std::upper_bound(
+                        this->heights.begin()
+                      , this->heights.end()
+                      , args[sample]
+                    );
+
+                    sample_cell = std::distance(this->heights.begin(), it);
+                }
+
+                // increment positions of markers above sample_cell
+                for (std::size_t i = sample_cell; i < b + 1; ++i)
+                {
+                    ++this->actual_positions[i];
+                }
+
+                // update desired position of markers 2 to num_cells + 1
+                // (desired position of first marker is always 1)
+                for (std::size_t i = 1; i < b + 1; ++i)
+                {
+                    this->desired_positions[i] += this->positions_increments[i];
+                }
+
+                // adjust heights of markers 2 to num_cells if necessary
+                for (std::size_t i = 1; i < b; ++i)
+                {
+                    // offset to desire position
+                    float_type d = this->desired_positions[i] - this->actual_positions[i];
+
+                    // offset to next position
+                    float_type dp = this->actual_positions[i + 1] - this->actual_positions[i];
+
+                    // offset to previous position
+                    float_type dm = this->actual_positions[i - 1] - this->actual_positions[i];
+
+                    // height ds
+                    float_type hp = (this->heights[i + 1] - this->heights[i]) / dp;
+                    float_type hm = (this->heights[i - 1] - this->heights[i]) / dm;
+
+                    if ( ( d >= 1. && dp > 1. ) || ( d <= -1. && dm < -1. ) )
+                    {
+                        short sign_d = static_cast<short>(d / std::abs(d));
+
+                        // try adjusting heights[i] using p-squared formula
+                        float_type h = this->heights[i] + sign_d / (dp - dm) * ( (sign_d - dm) * hp + (dp - sign_d) * hm );
+
+                        if ( this->heights[i - 1] < h && h < this->heights[i + 1] )
+                        {
+                            this->heights[i] = h;
+                        }
+                        else
+                        {
+                            // use linear formula
+                            if (d>0)
+                            {
+                                this->heights[i] += hp;
+                            }
+                            if (d<0)
+                            {
+                                this->heights[i] -= hm;
+                            }
+                        }
+                        this->actual_positions[i] += sign_d;
+                    }
+                }
+            }
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            if (this->is_dirty)
+            {
+                this->is_dirty = false;
+
+                // creates a vector of std::pair where each pair i holds
+                // the values heights[i] (x-axis of histogram) and
+                // actual_positions[i] / cnt (y-axis of histogram)
+
+                std::size_t cnt = count(args);
+
+                for (std::size_t i = 0; i < this->histogram.size(); ++i)
+                {
+                    this->histogram[i] = std::make_pair(this->heights[i], numeric::average(this->actual_positions[i], cnt));
+                }
+            }
+            //return histogram;
+            return make_iterator_range(this->histogram);
+        }
+
+    private:
+        std::size_t num_cells;            // number of cells b
+        array_type  heights;              // q_i
+        array_type  actual_positions;     // n_i
+        array_type  desired_positions;    // n'_i
+        array_type  positions_increments; // dn'_i
+        mutable histogram_type histogram; // histogram
+        mutable bool is_dirty;
+    };
+
+} // namespace detail
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::p_square_cumulative_distribution
+//
+namespace tag
+{
+    struct p_square_cumulative_distribution
+      : depends_on<count>
+      , p_square_cumulative_distribution_num_cells
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::p_square_cumulative_distribution_impl<mpl::_1> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::p_square_cumulative_distribution
+//
+namespace extract
+{
+    extractor<tag::p_square_cumulative_distribution> const p_square_cumulative_distribution = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(p_square_cumulative_distribution)
+}
+
+using extract::p_square_cumulative_distribution;
+
+// So that p_square_cumulative_distribution can be automatically substituted with
+// weighted_p_square_cumulative_distribution when the weight parameter is non-void
+template<>
+struct as_weighted_feature<tag::p_square_cumulative_distribution>
+{
+    typedef tag::weighted_p_square_cumulative_distribution type;
+};
+
+template<>
+struct feature_of<tag::weighted_p_square_cumulative_distribution>
+  : feature_of<tag::p_square_cumulative_distribution>
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/p_square_quantile.hpp b/boost/accumulators/statistics/p_square_quantile.hpp
new file mode 100644
index 0000000..844dfa7
--- /dev/null
+++ b/boost/accumulators/statistics/p_square_quantile.hpp
@@ -0,0 +1,257 @@
+///////////////////////////////////////////////////////////////////////////////
+// p_square_quantile.hpp
+//
+//  Copyright 2005 Daniel Egloff. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_P_SQUARE_QUANTILE_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_P_SQUARE_QUANTILE_HPP_DE_01_01_2006
+
+#include <cmath>
+#include <functional>
+#include <boost/array.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/parameters/quantile_probability.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // p_square_quantile_impl
+    //  single quantile estimation
+    /**
+        @brief Single quantile estimation with the \f$P^2\f$ algorithm
+
+        The \f$P^2\f$ algorithm estimates a quantile dynamically without storing samples. Instead of
+        storing the whole sample cumulative distribution, only five points (markers) are stored. The heights
+        of these markers are the minimum and the maximum of the samples and the current estimates of the
+        \f$(p/2)\f$-, \f$p\f$- and \f$(1+p)/2\f$-quantiles. Their positions are equal to the number
+        of samples that are smaller or equal to the markers. Each time a new samples is recorded, the
+        positions of the markers are updated and if necessary their heights are adjusted using a piecewise-
+        parabolic formula.
+
+        For further details, see
+
+        R. Jain and I. Chlamtac, The P^2 algorithmus fordynamic calculation of quantiles and
+        histograms without storing observations, Communications of the ACM,
+        Volume 28 (October), Number 10, 1985, p. 1076-1085.
+
+        @param quantile_probability
+    */
+    template<typename Sample, typename Impl>
+    struct p_square_quantile_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type float_type;
+        typedef array<float_type, 5> array_type;
+        // for boost::result_of
+        typedef float_type result_type;
+
+        template<typename Args>
+        p_square_quantile_impl(Args const &args)
+          : p(is_same<Impl, for_median>::value ? 0.5 : args[quantile_probability | 0.5])
+          , heights()
+          , actual_positions()
+          , desired_positions()
+          , positions_increments()
+        {
+            for(std::size_t i = 0; i < 5; ++i)
+            {
+                this->actual_positions[i] = i + 1;
+            }
+
+            this->desired_positions[0] = 1.;
+            this->desired_positions[1] = 1. + 2. * this->p;
+            this->desired_positions[2] = 1. + 4. * this->p;
+            this->desired_positions[3] = 3. + 2. * this->p;
+            this->desired_positions[4] = 5.;
+
+            this->positions_increments[0] = 0.;
+            this->positions_increments[1] = this->p / 2.;
+            this->positions_increments[2] = this->p;
+            this->positions_increments[3] = (1. + this->p) / 2.;
+            this->positions_increments[4] = 1.;
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            std::size_t cnt = count(args);
+
+            // accumulate 5 first samples
+            if(cnt <= 5)
+            {
+                this->heights[cnt - 1] = args[sample];
+
+                // complete the initialization of heights by sorting
+                if(cnt == 5)
+                {
+                    std::sort(this->heights.begin(), this->heights.end());
+                }
+            }
+            else
+            {
+                std::size_t sample_cell = 1; // k
+
+                // find cell k such that heights[k-1] <= args[sample] < heights[k] and ajust extreme values
+                if (args[sample] < this->heights[0])
+                {
+                    this->heights[0] = args[sample];
+                    sample_cell = 1;
+                }
+                else if (this->heights[4] <= args[sample])
+                {
+                    this->heights[4] = args[sample];
+                    sample_cell = 4;
+                }
+                else
+                {
+                    typedef typename array_type::iterator iterator;
+                    iterator it = std::upper_bound(
+                        this->heights.begin()
+                      , this->heights.end()
+                      , args[sample]
+                    );
+
+                    sample_cell = std::distance(this->heights.begin(), it);
+                }
+
+                // update positions of markers above sample_cell
+                for(std::size_t i = sample_cell; i < 5; ++i)
+                {
+                    ++this->actual_positions[i];
+                }
+
+                // update desired positions of all markers
+                for(std::size_t i = 0; i < 5; ++i)
+                {
+                    this->desired_positions[i] += this->positions_increments[i];
+                }
+
+                // adjust heights and actual positions of markers 1 to 3 if necessary
+                for(std::size_t i = 1; i <= 3; ++i)
+                {
+                    // offset to desired positions
+                    float_type d = this->desired_positions[i] - this->actual_positions[i];
+
+                    // offset to next position
+                    float_type dp = this->actual_positions[i + 1] - this->actual_positions[i];
+
+                    // offset to previous position
+                    float_type dm = this->actual_positions[i - 1] - this->actual_positions[i];
+
+                    // height ds
+                    float_type hp = (this->heights[i + 1] - this->heights[i]) / dp;
+                    float_type hm = (this->heights[i - 1] - this->heights[i]) / dm;
+
+                    if((d >= 1. && dp > 1.) || (d <= -1. && dm < -1.))
+                    {
+                        short sign_d = static_cast<short>(d / std::abs(d));
+
+                        // try adjusting heights[i] using p-squared formula
+                        float_type h = this->heights[i] + sign_d / (dp - dm) * ((sign_d - dm) * hp
+                                     + (dp - sign_d) * hm);
+
+                        if(this->heights[i - 1] < h && h < this->heights[i + 1])
+                        {
+                            this->heights[i] = h;
+                        }
+                        else
+                        {
+                            // use linear formula
+                            if(d > 0)
+                            {
+                                this->heights[i] += hp;
+                            }
+                            if(d < 0)
+                            {
+                                this->heights[i] -= hm;
+                            }
+                        }
+                        this->actual_positions[i] += sign_d;
+                    }
+                }
+            }
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->heights[2];
+        }
+
+    private:
+        float_type p;                    // the quantile probability p
+        array_type heights;              // q_i
+        array_type actual_positions;     // n_i
+        array_type desired_positions;    // n'_i
+        array_type positions_increments; // dn'_i
+    };
+
+} // namespace detail
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::p_square_quantile
+//
+namespace tag
+{
+    struct p_square_quantile
+      : depends_on<count>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::p_square_quantile_impl<mpl::_1, regular> impl;
+    };
+    struct p_square_quantile_for_median
+      : depends_on<count>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::p_square_quantile_impl<mpl::_1, for_median> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::p_square_quantile
+// extract::p_square_quantile_for_median
+//
+namespace extract
+{
+    extractor<tag::p_square_quantile> const p_square_quantile = {};
+    extractor<tag::p_square_quantile_for_median> const p_square_quantile_for_median = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(p_square_quantile)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(p_square_quantile_for_median)
+}
+
+using extract::p_square_quantile;
+using extract::p_square_quantile_for_median;
+
+// So that p_square_quantile can be automatically substituted with
+// weighted_p_square_quantile when the weight parameter is non-void
+template<>
+struct as_weighted_feature<tag::p_square_quantile>
+{
+    typedef tag::weighted_p_square_quantile type;
+};
+
+template<>
+struct feature_of<tag::weighted_p_square_quantile>
+  : feature_of<tag::p_square_quantile>
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/parameters/quantile_probability.hpp b/boost/accumulators/statistics/parameters/quantile_probability.hpp
new file mode 100644
index 0000000..be68f89
--- /dev/null
+++ b/boost/accumulators/statistics/parameters/quantile_probability.hpp
@@ -0,0 +1,20 @@
+///////////////////////////////////////////////////////////////////////////////
+// quantile_probability.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_PARAMETERS_QUANTILE_PROBABILITY_HPP_EAN_03_11_2005
+#define BOOST_ACCUMULATORS_STATISTICS_PARAMETERS_QUANTILE_PROBABILITY_HPP_EAN_03_11_2005
+
+#include <boost/parameter/keyword.hpp>
+
+namespace boost { namespace accumulators
+{
+
+BOOST_PARAMETER_KEYWORD(tag, quantile_probability)
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/peaks_over_threshold.hpp b/boost/accumulators/statistics/peaks_over_threshold.hpp
new file mode 100644
index 0000000..01f36f9
--- /dev/null
+++ b/boost/accumulators/statistics/peaks_over_threshold.hpp
@@ -0,0 +1,401 @@
+///////////////////////////////////////////////////////////////////////////////
+// peaks_over_threshold.hpp
+//
+//  Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_PEAKS_OVER_THRESHOLD_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_PEAKS_OVER_THRESHOLD_HPP_DE_01_01_2006
+
+#include <vector>
+#include <limits>
+#include <numeric>
+#include <functional>
+#include <boost/config/no_tr1/cmath.hpp> // pow
+#include <sstream> // stringstream
+#include <stdexcept> // runtime_error
+#include <boost/throw_exception.hpp>
+#include <boost/range.hpp>
+#include <boost/mpl/if.hpp>
+#include <boost/mpl/int.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/tuple/tuple.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/parameters/quantile_probability.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/tail.hpp>
+
+#ifdef _MSC_VER
+# pragma warning(push)
+# pragma warning(disable: 4127) // conditional expression is constant
+#endif
+
+namespace boost { namespace accumulators
+{
+
+///////////////////////////////////////////////////////////////////////////////
+// threshold_probability and threshold named parameters
+//
+BOOST_PARAMETER_NESTED_KEYWORD(tag, pot_threshold_value, threshold_value)
+BOOST_PARAMETER_NESTED_KEYWORD(tag, pot_threshold_probability, threshold_probability)
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // peaks_over_threshold_impl
+    //  works with an explicit threshold value and does not depend on order statistics
+    /**
+        @brief Peaks over Threshold Method for Quantile and Tail Mean Estimation
+
+        According to the theorem of Pickands-Balkema-de Haan, the distribution function \f$F_u(x)\f$ of
+        the excesses \f$x\f$ over some sufficiently high threshold \f$u\f$ of a distribution function \f$F(x)\f$
+        may be approximated by a generalized Pareto distribution
+        \f[
+            G_{\xi,\beta}(x) =
+            \left\{
+            \begin{array}{ll}
+                \beta^{-1}\left(1+\frac{\xi x}{\beta}\right)^{-1/\xi-1} & \textrm{if }\xi\neq0\\
+                \beta^{-1}\exp\left(-\frac{x}{\beta}\right) & \textrm{if }\xi=0,
+            \end{array}
+            \right.
+        \f]
+        with suitable parameters \f$\xi\f$ and \f$\beta\f$ that can be estimated, e.g., with the method of moments, cf.
+        Hosking and Wallis (1987),
+        \f[
+            \begin{array}{lll}
+            \hat{\xi} & = & \frac{1}{2}\left[1-\frac{(\hat{\mu}-u)^2}{\hat{\sigma}^2}\right]\\
+            \hat{\beta} & = & \frac{\hat{\mu}-u}{2}\left[\frac{(\hat{\mu}-u)^2}{\hat{\sigma}^2}+1\right],
+            \end{array}
+        \f]
+        \f$\hat{\mu}\f$ and \f$\hat{\sigma}^2\f$ being the empirical mean and variance of the samples over
+        the threshold \f$u\f$. Equivalently, the distribution function
+        \f$F_u(x-u)\f$ of the exceedances \f$x-u\f$ can be approximated by
+        \f$G_{\xi,\beta}(x-u)=G_{\xi,\beta,u}(x)\f$. Since for \f$x\geq u\f$ the distribution function \f$F(x)\f$
+        can be written as
+        \f[
+            F(x) = [1 - \P(X \leq u)]F_u(x - u) + \P(X \leq u)
+        \f]
+        and the probability \f$\P(X \leq u)\f$ can be approximated by the empirical distribution function
+        \f$F_n(u)\f$ evaluated at \f$u\f$, an estimator of \f$F(x)\f$ is given by
+        \f[
+            \widehat{F}(x) = [1 - F_n(u)]G_{\xi,\beta,u}(x) + F_n(u).
+        \f]
+        It can be shown that \f$\widehat{F}(x)\f$ is a generalized
+        Pareto distribution \f$G_{\xi,\bar{\beta},\bar{u}}(x)\f$ with \f$\bar{\beta}=\beta[1-F_n(u)]^{\xi}\f$
+        and \f$\bar{u}=u-\bar{\beta}\left\{[1-F_n(u)]^{-\xi}-1\right\}/\xi\f$. By inverting \f$\widehat{F}(x)\f$,
+        one obtains an estimator for the \f$\alpha\f$-quantile,
+        \f[
+            \hat{q}_{\alpha} = \bar{u} + \frac{\bar{\beta}}{\xi}\left[(1-\alpha)^{-\xi}-1\right],
+        \f]
+        and similarly an estimator for the (coherent) tail mean,
+        \f[
+            \widehat{CTM}_{\alpha} = \hat{q}_{\alpha} - \frac{\bar{\beta}}{\xi-1}(1-\alpha)^{-\xi},
+        \f]
+        cf. McNeil and Frey (2000).
+
+        Note that in case extreme values of the left tail are fitted, the distribution is mirrored with respect to the
+        \f$y\f$ axis such that the left tail can be treated as a right tail. The computed fit parameters thus define
+        the Pareto distribution that fits the mirrored left tail. When quantities like a quantile or a tail mean are
+        computed using the fit parameters obtained from the mirrored data, the result is mirrored back, yielding the
+        correct result.
+
+        For further details, see
+
+        J. R. M. Hosking and J. R. Wallis, Parameter and quantile estimation for the generalized Pareto distribution,
+        Technometrics, Volume 29, 1987, p. 339-349
+
+        A. J. McNeil and R. Frey, Estimation of Tail-Related Risk Measures for Heteroscedastic Financial Time Series:
+        an Extreme Value Approach, Journal of Empirical Finance, Volume 7, 2000, p. 271-300
+
+        @param quantile_probability
+        @param pot_threshold_value
+    */
+    template<typename Sample, typename LeftRight>
+    struct peaks_over_threshold_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type float_type;
+        // for boost::result_of
+        typedef boost::tuple<float_type, float_type, float_type> result_type;
+        // for left tail fitting, mirror the extreme values
+        typedef mpl::int_<is_same<LeftRight, left>::value ? -1 : 1> sign;
+
+        template<typename Args>
+        peaks_over_threshold_impl(Args const &args)
+          : Nu_(0)
+          , mu_(sign::value * numeric::average(args[sample | Sample()], (std::size_t)1))
+          , sigma2_(numeric::average(args[sample | Sample()], (std::size_t)1))
+          , threshold_(sign::value * args[pot_threshold_value])
+          , fit_parameters_(boost::make_tuple(0., 0., 0.))
+          , is_dirty_(true)
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            this->is_dirty_ = true;
+
+            if (sign::value * args[sample] > this->threshold_)
+            {
+                this->mu_ += args[sample];
+                this->sigma2_ += args[sample] * args[sample];
+                ++this->Nu_;
+            }
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            if (this->is_dirty_)
+            {
+                this->is_dirty_ = false;
+
+                std::size_t cnt = count(args);
+
+                this->mu_ = sign::value * numeric::average(this->mu_, this->Nu_);
+                this->sigma2_ = numeric::average(this->sigma2_, this->Nu_);
+                this->sigma2_ -= this->mu_ * this->mu_;
+
+                float_type threshold_probability = numeric::average(cnt - this->Nu_, cnt);
+
+                float_type tmp = numeric::average(( this->mu_ - this->threshold_ )*( this->mu_ - this->threshold_ ), this->sigma2_);
+                float_type xi_hat = 0.5 * ( 1. - tmp );
+                float_type beta_hat = 0.5 * ( this->mu_ - this->threshold_ ) * ( 1. + tmp );
+                float_type beta_bar = beta_hat * std::pow(1. - threshold_probability, xi_hat);
+                float_type u_bar = this->threshold_ - beta_bar * ( std::pow(1. - threshold_probability, -xi_hat) - 1.)/xi_hat;
+                this->fit_parameters_ = boost::make_tuple(u_bar, beta_bar, xi_hat);
+            }
+
+            return this->fit_parameters_;
+        }
+
+    private:
+        std::size_t Nu_;                     // number of samples larger than threshold
+        mutable float_type mu_;              // mean of Nu_ largest samples
+        mutable float_type sigma2_;          // variance of Nu_ largest samples
+        float_type threshold_;
+        mutable result_type fit_parameters_; // boost::tuple that stores fit parameters
+        mutable bool is_dirty_;
+    };
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // peaks_over_threshold_prob_impl
+    //  determines threshold from a given threshold probability using order statistics
+    /**
+        @brief Peaks over Threshold Method for Quantile and Tail Mean Estimation
+
+        @sa peaks_over_threshold_impl
+
+        @param quantile_probability
+        @param pot_threshold_probability
+    */
+    template<typename Sample, typename LeftRight>
+    struct peaks_over_threshold_prob_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type float_type;
+        // for boost::result_of
+        typedef boost::tuple<float_type, float_type, float_type> result_type;
+        // for left tail fitting, mirror the extreme values
+        typedef mpl::int_<is_same<LeftRight, left>::value ? -1 : 1> sign;
+
+        template<typename Args>
+        peaks_over_threshold_prob_impl(Args const &args)
+          : mu_(sign::value * numeric::average(args[sample | Sample()], (std::size_t)1))
+          , sigma2_(numeric::average(args[sample | Sample()], (std::size_t)1))
+          , threshold_probability_(args[pot_threshold_probability])
+          , fit_parameters_(boost::make_tuple(0., 0., 0.))
+          , is_dirty_(true)
+        {
+        }
+
+        void operator ()(dont_care)
+        {
+            this->is_dirty_ = true;
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            if (this->is_dirty_)
+            {
+                this->is_dirty_ = false;
+
+                std::size_t cnt = count(args);
+
+                // the n'th cached sample provides an approximate threshold value u
+                std::size_t n = static_cast<std::size_t>(
+                    std::ceil(
+                        cnt * ( ( is_same<LeftRight, left>::value ) ? this->threshold_probability_ : 1. - this->threshold_probability_ )
+                    )
+                );
+
+                // If n is in a valid range, return result, otherwise return NaN or throw exception
+                if ( n >= static_cast<std::size_t>(tail(args).size()))
+                {
+                    if (std::numeric_limits<float_type>::has_quiet_NaN)
+                    {
+                        return boost::make_tuple(
+                            std::numeric_limits<float_type>::quiet_NaN()
+                          , std::numeric_limits<float_type>::quiet_NaN()
+                          , std::numeric_limits<float_type>::quiet_NaN()
+                        );
+                    }
+                    else
+                    {
+                        std::ostringstream msg;
+                        msg << "index n = " << n << " is not in valid range [0, " << tail(args).size() << ")";
+                        boost::throw_exception(std::runtime_error(msg.str()));
+                        return boost::make_tuple(Sample(0), Sample(0), Sample(0));
+                    }
+                }
+                else
+                {
+                    float_type u = *(tail(args).begin() + n - 1) * sign::value;
+
+                    // compute mean and variance of samples above/under threshold value u
+                    for (std::size_t i = 0; i < n; ++i)
+                    {
+                        mu_ += *(tail(args).begin() + i);
+                        sigma2_ += *(tail(args).begin() + i) * (*(tail(args).begin() + i));
+                    }
+
+                    this->mu_ = sign::value * numeric::average(this->mu_, n);
+                    this->sigma2_ = numeric::average(this->sigma2_, n);
+                    this->sigma2_ -= this->mu_ * this->mu_;
+
+                    if (is_same<LeftRight, left>::value)
+                        this->threshold_probability_ = 1. - this->threshold_probability_;
+
+                    float_type tmp = numeric::average(( this->mu_ - u )*( this->mu_ - u ), this->sigma2_);
+                    float_type xi_hat = 0.5 * ( 1. - tmp );
+                    float_type beta_hat = 0.5 * ( this->mu_ - u ) * ( 1. + tmp );
+                    float_type beta_bar = beta_hat * std::pow(1. - threshold_probability_, xi_hat);
+                    float_type u_bar = u - beta_bar * ( std::pow(1. - threshold_probability_, -xi_hat) - 1.)/xi_hat;
+                    this->fit_parameters_ = boost::make_tuple(u_bar, beta_bar, xi_hat);
+                }
+            }
+
+            return this->fit_parameters_;
+        }
+
+    private:
+        mutable float_type mu_;                     // mean of samples above threshold u
+        mutable float_type sigma2_;                 // variance of samples above threshold u
+        mutable float_type threshold_probability_;
+        mutable result_type fit_parameters_;        // boost::tuple that stores fit parameters
+        mutable bool is_dirty_;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::peaks_over_threshold
+//
+namespace tag
+{
+    template<typename LeftRight>
+    struct peaks_over_threshold
+      : depends_on<count>
+      , pot_threshold_value
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::peaks_over_threshold_impl<mpl::_1, LeftRight> impl;
+    };
+
+    template<typename LeftRight>
+    struct peaks_over_threshold_prob
+      : depends_on<count, tail<LeftRight> >
+      , pot_threshold_probability
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::peaks_over_threshold_prob_impl<mpl::_1, LeftRight> impl;
+    };
+
+    struct abstract_peaks_over_threshold
+      : depends_on<>
+    {
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::peaks_over_threshold
+//
+namespace extract
+{
+    extractor<tag::abstract_peaks_over_threshold> const peaks_over_threshold = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(peaks_over_threshold)
+}
+
+using extract::peaks_over_threshold;
+
+// peaks_over_threshold<LeftRight>(with_threshold_value) -> peaks_over_threshold<LeftRight>
+template<typename LeftRight>
+struct as_feature<tag::peaks_over_threshold<LeftRight>(with_threshold_value)>
+{
+    typedef tag::peaks_over_threshold<LeftRight> type;
+};
+
+// peaks_over_threshold<LeftRight>(with_threshold_probability) -> peaks_over_threshold_prob<LeftRight>
+template<typename LeftRight>
+struct as_feature<tag::peaks_over_threshold<LeftRight>(with_threshold_probability)>
+{
+    typedef tag::peaks_over_threshold_prob<LeftRight> type;
+};
+
+template<typename LeftRight>
+struct feature_of<tag::peaks_over_threshold<LeftRight> >
+  : feature_of<tag::abstract_peaks_over_threshold>
+{
+};
+
+template<typename LeftRight>
+struct feature_of<tag::peaks_over_threshold_prob<LeftRight> >
+  : feature_of<tag::abstract_peaks_over_threshold>
+{
+};
+
+// So that peaks_over_threshold can be automatically substituted
+// with weighted_peaks_over_threshold when the weight parameter is non-void.
+template<typename LeftRight>
+struct as_weighted_feature<tag::peaks_over_threshold<LeftRight> >
+{
+    typedef tag::weighted_peaks_over_threshold<LeftRight> type;
+};
+
+template<typename LeftRight>
+struct feature_of<tag::weighted_peaks_over_threshold<LeftRight> >
+  : feature_of<tag::peaks_over_threshold<LeftRight> >
+{};
+
+// So that peaks_over_threshold_prob can be automatically substituted
+// with weighted_peaks_over_threshold_prob when the weight parameter is non-void.
+template<typename LeftRight>
+struct as_weighted_feature<tag::peaks_over_threshold_prob<LeftRight> >
+{
+    typedef tag::weighted_peaks_over_threshold_prob<LeftRight> type;
+};
+
+template<typename LeftRight>
+struct feature_of<tag::weighted_peaks_over_threshold_prob<LeftRight> >
+  : feature_of<tag::peaks_over_threshold_prob<LeftRight> >
+{};
+
+}} // namespace boost::accumulators
+
+#ifdef _MSC_VER
+# pragma warning(pop)
+#endif
+
+#endif
diff --git a/boost/accumulators/statistics/pot_quantile.hpp b/boost/accumulators/statistics/pot_quantile.hpp
new file mode 100644
index 0000000..aceff8c
--- /dev/null
+++ b/boost/accumulators/statistics/pot_quantile.hpp
@@ -0,0 +1,205 @@
+///////////////////////////////////////////////////////////////////////////////
+// pot_quantile.hpp
+//
+//  Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_POT_QUANTILE_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_POT_QUANTILE_HPP_DE_01_01_2006
+
+#include <vector>
+#include <limits>
+#include <numeric>
+#include <functional>
+#include <boost/parameter/keyword.hpp>
+#include <boost/tuple/tuple.hpp>
+#include <boost/mpl/if.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/tail.hpp>
+#include <boost/accumulators/statistics/peaks_over_threshold.hpp>
+#include <boost/accumulators/statistics/weighted_peaks_over_threshold.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // pot_quantile_impl
+    //
+    /**
+        @brief Quantile Estimation based on Peaks over Threshold Method (for both left and right tails)
+
+        Computes an estimate
+        \f[
+            \hat{q}_{\alpha} = \bar{u} + \frac{\bar{\beta}}{\xi}\left[(1-\alpha)^{-\xi}-1\right]
+        \f]
+        for a right or left extreme quantile, \f$\bar[u]\f$, \f$\bar{\beta}\f$ and \f$\xi\f$ being the parameters of the
+        generalized Pareto distribution that approximates the right tail of the distribution (or the mirrored left tail,
+        in case the left tail is used). In the latter case, the result is mirrored back, yielding the correct result.
+    */
+    template<typename Sample, typename Impl, typename LeftRight>
+    struct pot_quantile_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type float_type;
+        // for boost::result_of
+        typedef float_type result_type;
+
+        pot_quantile_impl(dont_care)
+          : sign_((is_same<LeftRight, left>::value) ? -1 : 1)
+        {
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            typedef
+                typename mpl::if_<
+                    is_same<Impl, weighted>
+                  , tag::weighted_peaks_over_threshold<LeftRight>
+                  , tag::peaks_over_threshold<LeftRight>
+                >::type
+            peaks_over_threshold_tag;
+
+            extractor<peaks_over_threshold_tag> const some_peaks_over_threshold = {};
+
+            float_type u_bar    = some_peaks_over_threshold(args).template get<0>();
+            float_type beta_bar = some_peaks_over_threshold(args).template get<1>();
+            float_type xi_hat   = some_peaks_over_threshold(args).template get<2>();
+
+            return this->sign_ * (u_bar + beta_bar/xi_hat * ( std::pow(
+                    is_same<LeftRight, left>::value ? args[quantile_probability] : 1. - args[quantile_probability]
+                , -xi_hat
+              ) - 1.));
+        }
+
+    private:
+        short sign_; // if the fit parameters from the mirrored left tail extreme values are used, mirror back the result
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::pot_quantile<>
+// tag::pot_quantile_prob<>
+// tag::weighted_pot_quantile<>
+// tag::weighted_pot_quantile_prob<>
+//
+namespace tag
+{
+    template<typename LeftRight>
+    struct pot_quantile
+      : depends_on<peaks_over_threshold<LeftRight> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::pot_quantile_impl<mpl::_1, unweighted, LeftRight> impl;
+    };
+    template<typename LeftRight>
+    struct pot_quantile_prob
+      : depends_on<peaks_over_threshold_prob<LeftRight> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::pot_quantile_impl<mpl::_1, unweighted, LeftRight> impl;
+    };
+    template<typename LeftRight>
+    struct weighted_pot_quantile
+      : depends_on<weighted_peaks_over_threshold<LeftRight> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::pot_quantile_impl<mpl::_1, weighted, LeftRight> impl;
+    };
+    template<typename LeftRight>
+    struct weighted_pot_quantile_prob
+      : depends_on<weighted_peaks_over_threshold_prob<LeftRight> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::pot_quantile_impl<mpl::_1, weighted, LeftRight> impl;
+    };
+}
+
+// pot_quantile<LeftRight>(with_threshold_value) -> pot_quantile<LeftRight>
+template<typename LeftRight>
+struct as_feature<tag::pot_quantile<LeftRight>(with_threshold_value)>
+{
+    typedef tag::pot_quantile<LeftRight> type;
+};
+
+// pot_quantile<LeftRight>(with_threshold_probability) -> pot_quantile_prob<LeftRight>
+template<typename LeftRight>
+struct as_feature<tag::pot_quantile<LeftRight>(with_threshold_probability)>
+{
+    typedef tag::pot_quantile_prob<LeftRight> type;
+};
+
+// weighted_pot_quantile<LeftRight>(with_threshold_value) -> weighted_pot_quantile<LeftRight>
+template<typename LeftRight>
+struct as_feature<tag::weighted_pot_quantile<LeftRight>(with_threshold_value)>
+{
+    typedef tag::weighted_pot_quantile<LeftRight> type;
+};
+
+// weighted_pot_quantile<LeftRight>(with_threshold_probability) -> weighted_pot_quantile_prob<LeftRight>
+template<typename LeftRight>
+struct as_feature<tag::weighted_pot_quantile<LeftRight>(with_threshold_probability)>
+{
+    typedef tag::weighted_pot_quantile_prob<LeftRight> type;
+};
+
+// for the purposes of feature-based dependency resolution,
+// pot_quantile<LeftRight> and pot_quantile_prob<LeftRight> provide
+// the same feature as quantile
+template<typename LeftRight>
+struct feature_of<tag::pot_quantile<LeftRight> >
+  : feature_of<tag::quantile>
+{
+};
+
+template<typename LeftRight>
+struct feature_of<tag::pot_quantile_prob<LeftRight> >
+  : feature_of<tag::quantile>
+{
+};
+
+// So that pot_quantile can be automatically substituted
+// with weighted_pot_quantile when the weight parameter is non-void.
+template<typename LeftRight>
+struct as_weighted_feature<tag::pot_quantile<LeftRight> >
+{
+    typedef tag::weighted_pot_quantile<LeftRight> type;
+};
+
+template<typename LeftRight>
+struct feature_of<tag::weighted_pot_quantile<LeftRight> >
+  : feature_of<tag::pot_quantile<LeftRight> >
+{
+};
+
+// So that pot_quantile_prob can be automatically substituted
+// with weighted_pot_quantile_prob when the weight parameter is non-void.
+template<typename LeftRight>
+struct as_weighted_feature<tag::pot_quantile_prob<LeftRight> >
+{
+    typedef tag::weighted_pot_quantile_prob<LeftRight> type;
+};
+
+template<typename LeftRight>
+struct feature_of<tag::weighted_pot_quantile_prob<LeftRight> >
+  : feature_of<tag::pot_quantile_prob<LeftRight> >
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/pot_tail_mean.hpp b/boost/accumulators/statistics/pot_tail_mean.hpp
new file mode 100644
index 0000000..088ef98
--- /dev/null
+++ b/boost/accumulators/statistics/pot_tail_mean.hpp
@@ -0,0 +1,211 @@
+///////////////////////////////////////////////////////////////////////////////
+// pot_tail_mean.hpp
+//
+//  Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_POT_TAIL_MEAN_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_POT_TAIL_MEAN_HPP_DE_01_01_2006
+
+#include <vector>
+#include <limits>
+#include <numeric>
+#include <functional>
+#include <boost/range.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/tuple/tuple.hpp>
+#include <boost/mpl/if.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/peaks_over_threshold.hpp>
+#include <boost/accumulators/statistics/weighted_peaks_over_threshold.hpp>
+#include <boost/accumulators/statistics/pot_quantile.hpp>
+#include <boost/accumulators/statistics/tail_mean.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // pot_tail_mean_impl
+    //
+    /**
+        @brief Estimation of the (coherent) tail mean based on the peaks over threshold method (for both left and right tails)
+
+        Computes an estimate for the (coherent) tail mean
+        \f[
+            \widehat{CTM}_{\alpha} = \hat{q}_{\alpha} - \frac{\bar{\beta}}{\xi-1}(1-\alpha)^{-\xi},
+        \f]
+        where \f$\bar[u]\f$, \f$\bar{\beta}\f$ and \f$\xi\f$ are the parameters of the
+        generalized Pareto distribution that approximates the right tail of the distribution (or the
+        mirrored left tail, in case the left tail is used). In the latter case, the result is mirrored
+        back, yielding the correct result.
+    */
+    template<typename Sample, typename Impl, typename LeftRight>
+    struct pot_tail_mean_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type float_type;
+        // for boost::result_of
+        typedef float_type result_type;
+
+        pot_tail_mean_impl(dont_care)
+          : sign_((is_same<LeftRight, left>::value) ? -1 : 1)
+        {
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            typedef
+                typename mpl::if_<
+                    is_same<Impl, weighted>
+                  , tag::weighted_peaks_over_threshold<LeftRight>
+                  , tag::peaks_over_threshold<LeftRight>
+                >::type
+            peaks_over_threshold_tag;
+
+            typedef
+                typename mpl::if_<
+                    is_same<Impl, weighted>
+                  , tag::weighted_pot_quantile<LeftRight>
+                  , tag::pot_quantile<LeftRight>
+                >::type
+            pot_quantile_tag;
+
+            extractor<peaks_over_threshold_tag> const some_peaks_over_threshold = {};
+            extractor<pot_quantile_tag> const some_pot_quantile = {};
+
+            float_type beta_bar = some_peaks_over_threshold(args).template get<1>();
+            float_type xi_hat   = some_peaks_over_threshold(args).template get<2>();
+
+            return some_pot_quantile(args) - this->sign_ * beta_bar/( xi_hat - 1. ) * std::pow(
+                is_same<LeftRight, left>::value ? args[quantile_probability] : 1. - args[quantile_probability]
+              , -xi_hat);
+        }
+    private:
+        short sign_; // if the fit parameters from the mirrored left tail extreme values are used, mirror back the result
+    };
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::pot_tail_mean
+// tag::pot_tail_mean_prob
+//
+namespace tag
+{
+    template<typename LeftRight>
+    struct pot_tail_mean
+      : depends_on<peaks_over_threshold<LeftRight>, pot_quantile<LeftRight> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::pot_tail_mean_impl<mpl::_1, unweighted, LeftRight> impl;
+    };
+    template<typename LeftRight>
+    struct pot_tail_mean_prob
+      : depends_on<peaks_over_threshold_prob<LeftRight>, pot_quantile_prob<LeftRight> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::pot_tail_mean_impl<mpl::_1, unweighted, LeftRight> impl;
+    };
+    template<typename LeftRight>
+    struct weighted_pot_tail_mean
+      : depends_on<weighted_peaks_over_threshold<LeftRight>, weighted_pot_quantile<LeftRight> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::pot_tail_mean_impl<mpl::_1, weighted, LeftRight> impl;
+    };
+    template<typename LeftRight>
+    struct weighted_pot_tail_mean_prob
+      : depends_on<weighted_peaks_over_threshold_prob<LeftRight>, weighted_pot_quantile_prob<LeftRight> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::pot_tail_mean_impl<mpl::_1, weighted, LeftRight> impl;
+    };
+}
+
+// pot_tail_mean<LeftRight>(with_threshold_value) -> pot_tail_mean<LeftRight>
+template<typename LeftRight>
+struct as_feature<tag::pot_tail_mean<LeftRight>(with_threshold_value)>
+{
+    typedef tag::pot_tail_mean<LeftRight> type;
+};
+
+// pot_tail_mean<LeftRight>(with_threshold_probability) -> pot_tail_mean_prob<LeftRight>
+template<typename LeftRight>
+struct as_feature<tag::pot_tail_mean<LeftRight>(with_threshold_probability)>
+{
+    typedef tag::pot_tail_mean_prob<LeftRight> type;
+};
+
+// weighted_pot_tail_mean<LeftRight>(with_threshold_value) -> weighted_pot_tail_mean<LeftRight>
+template<typename LeftRight>
+struct as_feature<tag::weighted_pot_tail_mean<LeftRight>(with_threshold_value)>
+{
+    typedef tag::weighted_pot_tail_mean<LeftRight> type;
+};
+
+// weighted_pot_tail_mean<LeftRight>(with_threshold_probability) -> weighted_pot_tail_mean_prob<LeftRight>
+template<typename LeftRight>
+struct as_feature<tag::weighted_pot_tail_mean<LeftRight>(with_threshold_probability)>
+{
+    typedef tag::weighted_pot_tail_mean_prob<LeftRight> type;
+};
+
+// for the purposes of feature-based dependency resolution,
+// pot_tail_mean<LeftRight> and pot_tail_mean_prob<LeftRight> provide
+// the same feature as tail_mean
+template<typename LeftRight>
+struct feature_of<tag::pot_tail_mean<LeftRight> >
+  : feature_of<tag::tail_mean>
+{
+};
+
+template<typename LeftRight>
+struct feature_of<tag::pot_tail_mean_prob<LeftRight> >
+  : feature_of<tag::tail_mean>
+{
+};
+
+// So that pot_tail_mean can be automatically substituted
+// with weighted_pot_tail_mean when the weight parameter is non-void.
+template<typename LeftRight>
+struct as_weighted_feature<tag::pot_tail_mean<LeftRight> >
+{
+    typedef tag::weighted_pot_tail_mean<LeftRight> type;
+};
+
+template<typename LeftRight>
+struct feature_of<tag::weighted_pot_tail_mean<LeftRight> >
+  : feature_of<tag::pot_tail_mean<LeftRight> >
+{
+};
+
+// So that pot_tail_mean_prob can be automatically substituted
+// with weighted_pot_tail_mean_prob when the weight parameter is non-void.
+template<typename LeftRight>
+struct as_weighted_feature<tag::pot_tail_mean_prob<LeftRight> >
+{
+    typedef tag::weighted_pot_tail_mean_prob<LeftRight> type;
+};
+
+template<typename LeftRight>
+struct feature_of<tag::weighted_pot_tail_mean_prob<LeftRight> >
+  : feature_of<tag::pot_tail_mean_prob<LeftRight> >
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/rolling_count.hpp b/boost/accumulators/statistics/rolling_count.hpp
new file mode 100644
index 0000000..1e34f76
--- /dev/null
+++ b/boost/accumulators/statistics/rolling_count.hpp
@@ -0,0 +1,80 @@
+///////////////////////////////////////////////////////////////////////////////
+// rolling_count.hpp
+//
+// Copyright 2008 Eric Niebler. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying file
+// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_ROLLING_COUNT_HPP_EAN_26_12_2008
+#define BOOST_ACCUMULATORS_STATISTICS_ROLLING_COUNT_HPP_EAN_26_12_2008
+
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/rolling_window.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // rolling_count_impl
+    //    returns the count of elements in the rolling window
+    template<typename Sample>
+    struct rolling_count_impl
+      : accumulator_base
+    {
+        typedef std::size_t result_type;
+
+        rolling_count_impl(dont_care)
+        {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            return static_cast<std::size_t>(rolling_window_plus1(args).size()) - is_rolling_window_plus1_full(args);
+        }
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::rolling_count
+//
+namespace tag
+{
+    struct rolling_count
+      : depends_on< rolling_window_plus1 >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::rolling_count_impl< mpl::_1 > impl;
+
+        #ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
+        /// tag::rolling_window::window_size named parameter
+        static boost::parameter::keyword<tag::rolling_window_size> const window_size;
+        #endif
+    };
+} // namespace tag
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::rolling_count
+//
+namespace extract
+{
+    extractor<tag::rolling_count> const rolling_count = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(rolling_count)
+}
+
+using extract::rolling_count;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/rolling_mean.hpp b/boost/accumulators/statistics/rolling_mean.hpp
new file mode 100644
index 0000000..ddcbaa3
--- /dev/null
+++ b/boost/accumulators/statistics/rolling_mean.hpp
@@ -0,0 +1,81 @@
+///////////////////////////////////////////////////////////////////////////////
+// rolling_mean.hpp
+//
+// Copyright 2008 Eric Niebler. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying file
+// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_ROLLING_MEAN_HPP_EAN_26_12_2008
+#define BOOST_ACCUMULATORS_STATISTICS_ROLLING_MEAN_HPP_EAN_26_12_2008
+
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/rolling_sum.hpp>
+#include <boost/accumulators/statistics/rolling_count.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // rolling_mean_impl
+    //    returns the unshifted results from the shifted rolling window
+    template<typename Sample>
+    struct rolling_mean_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type result_type;
+
+        rolling_mean_impl(dont_care)
+        {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            return numeric::average(rolling_sum(args), rolling_count(args));
+        }
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::rolling_mean
+//
+namespace tag
+{
+    struct rolling_mean
+      : depends_on< rolling_sum, rolling_count >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::rolling_mean_impl< mpl::_1 > impl;
+
+        #ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
+        /// tag::rolling_window::window_size named parameter
+        static boost::parameter::keyword<tag::rolling_window_size> const window_size;
+        #endif
+    };
+} // namespace tag
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::rolling_mean
+//
+namespace extract
+{
+    extractor<tag::rolling_mean> const rolling_mean = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(rolling_mean)
+}
+
+using extract::rolling_mean;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/rolling_sum.hpp b/boost/accumulators/statistics/rolling_sum.hpp
new file mode 100644
index 0000000..b41ab39
--- /dev/null
+++ b/boost/accumulators/statistics/rolling_sum.hpp
@@ -0,0 +1,93 @@
+///////////////////////////////////////////////////////////////////////////////
+// rolling_sum.hpp
+//
+// Copyright 2008 Eric Niebler. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying file
+// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_ROLLING_SUM_HPP_EAN_26_12_2008
+#define BOOST_ACCUMULATORS_STATISTICS_ROLLING_SUM_HPP_EAN_26_12_2008
+
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/rolling_window.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // rolling_sum_impl
+    //    returns the sum of the samples in the rolling window
+    template<typename Sample>
+    struct rolling_sum_impl
+      : accumulator_base
+    {
+        typedef Sample result_type;
+
+        template<typename Args>
+        rolling_sum_impl(Args const &args)
+          : sum_(args[sample | Sample()])
+        {}
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            if(is_rolling_window_plus1_full(args))
+            {
+                this->sum_ -= rolling_window_plus1(args).front();
+            }
+            this->sum_ += args[sample];
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            return this->sum_;
+        }
+
+    private:
+        Sample sum_;
+    };
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::rolling_sum
+//
+namespace tag
+{
+    struct rolling_sum
+      : depends_on< rolling_window_plus1 >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::rolling_sum_impl< mpl::_1 > impl;
+
+        #ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
+        /// tag::rolling_window::window_size named parameter
+        static boost::parameter::keyword<tag::rolling_window_size> const window_size;
+        #endif
+    };
+} // namespace tag
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::rolling_sum
+//
+namespace extract
+{
+    extractor<tag::rolling_sum> const rolling_sum = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(rolling_sum)
+}
+
+using extract::rolling_sum;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/rolling_window.hpp b/boost/accumulators/statistics/rolling_window.hpp
new file mode 100644
index 0000000..d2f4b0d
--- /dev/null
+++ b/boost/accumulators/statistics/rolling_window.hpp
@@ -0,0 +1,169 @@
+///////////////////////////////////////////////////////////////////////////////
+// rolling_window.hpp
+//
+// Copyright 2008 Eric Niebler. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying file
+// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_ROLLING_WINDOW_HPP_EAN_26_12_2008
+#define BOOST_ACCUMULATORS_STATISTICS_ROLLING_WINDOW_HPP_EAN_26_12_2008
+
+#include <cstddef>
+#include <boost/version.hpp>
+#include <boost/assert.hpp>
+#include <boost/circular_buffer.hpp>
+#include <boost/range/iterator_range.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/parameters/accumulator.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+
+namespace boost { namespace accumulators
+{
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::rolling_window::size named parameter
+BOOST_PARAMETER_NESTED_KEYWORD(tag, rolling_window_size, window_size)
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // rolling_window_plus1_impl
+    //    stores the latest N+1 samples, where N is specified at construction time
+    //    with the rolling_window_size named parameter
+    template<typename Sample>
+    struct rolling_window_plus1_impl
+      : accumulator_base
+    {
+        typedef typename circular_buffer<Sample>::const_iterator const_iterator;
+        typedef iterator_range<const_iterator> result_type;
+
+        template<typename Args>
+        rolling_window_plus1_impl(Args const & args)
+          : buffer_(args[rolling_window_size] + 1)
+        {}
+
+        #if BOOST_VERSION < 103600
+        // Before Boost 1.36, copying a circular buffer didn't copy
+        // it's capacity, and we need that behavior.
+        rolling_window_plus1_impl(rolling_window_plus1_impl const &that)
+          : buffer_(that.buffer_)
+        {
+            this->buffer_.set_capacity(that.buffer_.capacity());
+        }
+
+        rolling_window_plus1_impl &operator =(rolling_window_plus1_impl const &that)
+        {
+            this->buffer_ = that.buffer_;
+            this->buffer_.set_capacity(that.buffer_.capacity());
+        }
+        #endif
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            this->buffer_.push_back(args[sample]);
+        }
+
+        bool full() const
+        {
+            return this->buffer_.full();
+        }
+
+        // The result of a shifted rolling window is the range including
+        // everything except the most recently added element.
+        result_type result(dont_care) const
+        {
+            return result_type(this->buffer_.begin(), this->buffer_.end());
+        }
+
+    private:
+        circular_buffer<Sample> buffer_;
+    };
+
+    template<typename Args>
+    bool is_rolling_window_plus1_full(Args const &args)
+    {
+        return find_accumulator<tag::rolling_window_plus1>(args[accumulator]).full();
+    }
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // rolling_window_impl
+    //    stores the latest N samples, where N is specified at construction type
+    //    with the rolling_window_size named parameter
+    template<typename Sample>
+    struct rolling_window_impl
+      : accumulator_base
+    {
+        typedef typename circular_buffer<Sample>::const_iterator const_iterator;
+        typedef iterator_range<const_iterator> result_type;
+
+        rolling_window_impl(dont_care)
+        {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            return rolling_window_plus1(args).advance_begin(is_rolling_window_plus1_full(args));
+        }
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::rolling_window_plus1
+// tag::rolling_window
+//
+namespace tag
+{
+    struct rolling_window_plus1
+      : depends_on<>
+      , tag::rolling_window_size
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::rolling_window_plus1_impl< mpl::_1 > impl;
+
+        #ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
+        /// tag::rolling_window::size named parameter
+        static boost::parameter::keyword<tag::rolling_window_size> const window_size;
+        #endif
+    };
+
+    struct rolling_window
+      : depends_on< rolling_window_plus1 >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::rolling_window_impl< mpl::_1 > impl;
+
+        #ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
+        /// tag::rolling_window::size named parameter
+        static boost::parameter::keyword<tag::rolling_window_size> const window_size;
+        #endif
+    };
+
+} // namespace tag
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::rolling_window_plus1
+// extract::rolling_window
+//
+namespace extract
+{
+    extractor<tag::rolling_window_plus1> const rolling_window_plus1 = {};
+    extractor<tag::rolling_window> const rolling_window = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(rolling_window_plus1)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(rolling_window)
+}
+
+using extract::rolling_window_plus1;
+using extract::rolling_window;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/skewness.hpp b/boost/accumulators/statistics/skewness.hpp
new file mode 100644
index 0000000..2e29018
--- /dev/null
+++ b/boost/accumulators/statistics/skewness.hpp
@@ -0,0 +1,114 @@
+///////////////////////////////////////////////////////////////////////////////
+// skewness.hpp
+//
+//  Copyright 2006 Olivier Gygi, Daniel Egloff. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_SKEWNESS_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_SKEWNESS_HPP_EAN_28_10_2005
+
+#include <limits>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/moment.hpp>
+#include <boost/accumulators/statistics/mean.hpp>
+
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // skewness_impl
+    /**
+        @brief Skewness estimation
+
+        The skewness of a sample distribution is defined as the ratio of the 3rd central moment and the \f$ 3/2 \f$-th power
+        of the 2nd central moment (the variance) of the sampless 3. The skewness can also be expressed by the simple moments:
+
+        \f[
+            \hat{g}_1 =
+                \frac
+                {\widehat{m}_n^{(3)}-3\widehat{m}_n^{(2)}\hat{\mu}_n+2\hat{\mu}_n^3}
+                {\left(\widehat{m}_n^{(2)} - \hat{\mu}_n^{2}\right)^{3/2}}
+        \f]
+
+        where \f$ \widehat{m}_n^{(i)} \f$ are the \f$ i \f$-th moment and \f$ \hat{\mu}_n \f$ the mean (first moment) of the
+        \f$ n \f$ samples.
+    */
+    template<typename Sample>
+    struct skewness_impl
+      : accumulator_base
+    {
+        // for boost::result_of
+        typedef typename numeric::functional::average<Sample, Sample>::result_type result_type;
+
+        skewness_impl(dont_care)
+        {
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            return numeric::average(
+                        accumulators::moment<3>(args)
+                        - 3. * accumulators::moment<2>(args) * mean(args)
+                        + 2. * mean(args) * mean(args) * mean(args)
+                      , ( accumulators::moment<2>(args) - mean(args) * mean(args) )
+                        * std::sqrt( accumulators::moment<2>(args) - mean(args) * mean(args) )
+                   );
+        }
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::skewness
+//
+namespace tag
+{
+    struct skewness
+      : depends_on<mean, moment<2>, moment<3> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::skewness_impl<mpl::_1> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::skewness
+//
+namespace extract
+{
+    extractor<tag::skewness> const skewness = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(skewness)
+}
+
+using extract::skewness;
+
+// So that skewness can be automatically substituted with
+// weighted_skewness when the weight parameter is non-void
+template<>
+struct as_weighted_feature<tag::skewness>
+{
+    typedef tag::weighted_skewness type;
+};
+
+template<>
+struct feature_of<tag::weighted_skewness>
+  : feature_of<tag::skewness>
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/stats.hpp b/boost/accumulators/statistics/stats.hpp
new file mode 100644
index 0000000..22c4ede
--- /dev/null
+++ b/boost/accumulators/statistics/stats.hpp
@@ -0,0 +1,29 @@
+///////////////////////////////////////////////////////////////////////////////
+/// \file stats.hpp
+/// Contains the stats<> template.
+///
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_STATS_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_STATS_HPP_EAN_28_10_2005
+
+#include <boost/preprocessor/repetition/enum_params.hpp>
+#include <boost/mpl/vector.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+
+namespace boost { namespace accumulators
+{
+
+///////////////////////////////////////////////////////////////////////////////
+/// An MPL sequence of statistics.
+template<BOOST_PP_ENUM_PARAMS(BOOST_ACCUMULATORS_MAX_FEATURES, typename Stat)>
+struct stats
+  : mpl::vector<BOOST_PP_ENUM_PARAMS(BOOST_ACCUMULATORS_MAX_FEATURES, Stat)>
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/sum.hpp b/boost/accumulators/statistics/sum.hpp
new file mode 100644
index 0000000..126ce24
--- /dev/null
+++ b/boost/accumulators/statistics/sum.hpp
@@ -0,0 +1,141 @@
+///////////////////////////////////////////////////////////////////////////////
+// sum.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_SUM_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_SUM_HPP_EAN_28_10_2005
+
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/parameters/weight.hpp>
+#include <boost/accumulators/framework/accumulators/external_accumulator.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // sum_impl
+    template<typename Sample, typename Tag>
+    struct sum_impl
+      : accumulator_base
+    {
+        // for boost::result_of
+        typedef Sample result_type;
+
+        template<typename Args>
+        sum_impl(Args const &args)
+          : sum(args[parameter::keyword<Tag>::get() | Sample()])
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            // what about overflow?
+            this->sum += args[parameter::keyword<Tag>::get()];
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->sum;
+        }
+
+    private:
+
+        Sample sum;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::sum
+// tag::sum_of_weights
+// tag::sum_of_variates
+//
+namespace tag
+{
+    struct sum
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::sum_impl<mpl::_1, tag::sample> impl;
+    };
+
+    struct sum_of_weights
+      : depends_on<>
+    {
+        typedef mpl::true_ is_weight_accumulator;
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::sum_impl<mpl::_2, tag::weight> impl;
+    };
+
+    template<typename VariateType, typename VariateTag>
+    struct sum_of_variates
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef mpl::always<accumulators::impl::sum_impl<VariateType, VariateTag> > impl;
+    };
+
+    struct abstract_sum_of_variates
+      : depends_on<>
+    {
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::sum
+// extract::sum_of_weights
+// extract::sum_of_variates
+//
+namespace extract
+{
+    extractor<tag::sum> const sum = {};
+    extractor<tag::sum_of_weights> const sum_of_weights = {};
+    extractor<tag::abstract_sum_of_variates> const sum_of_variates = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(sum)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(sum_of_weights)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(sum_of_variates)
+}
+
+using extract::sum;
+using extract::sum_of_weights;
+using extract::sum_of_variates;
+
+// So that mean can be automatically substituted with
+// weighted_mean when the weight parameter is non-void.
+template<>
+struct as_weighted_feature<tag::sum>
+{
+    typedef tag::weighted_sum type;
+};
+
+template<>
+struct feature_of<tag::weighted_sum>
+  : feature_of<tag::sum>
+{};
+
+template<typename VariateType, typename VariateTag>
+struct feature_of<tag::sum_of_variates<VariateType, VariateTag> >
+  : feature_of<tag::abstract_sum_of_variates>
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/sum_kahan.hpp b/boost/accumulators/statistics/sum_kahan.hpp
new file mode 100644
index 0000000..b5b9958
--- /dev/null
+++ b/boost/accumulators/statistics/sum_kahan.hpp
@@ -0,0 +1,188 @@
+///////////////////////////////////////////////////////////////////////////////
+// sum_kahan.hpp
+//
+//  Copyright 2010 Gaetano Mendola, 2011 Simon West. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_SUM_KAHAN_HPP_EAN_26_07_2010
+#define BOOST_ACCUMULATORS_STATISTICS_SUM_KAHAN_HPP_EAN_26_07_2010
+
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/sum.hpp>
+#include <boost/accumulators/statistics/weighted_sum_kahan.hpp>
+#include <boost/numeric/conversion/cast.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+
+#if _MSC_VER > 1400
+# pragma float_control(push)
+# pragma float_control(precise, on)
+#endif
+
+template<typename Sample, typename Tag>
+struct sum_kahan_impl
+  : accumulator_base
+{
+    typedef Sample result_type;
+
+    ////////////////////////////////////////////////////////////////////////////
+    // sum_kahan_impl
+    /**
+        @brief Kahan summation algorithm
+
+        The Kahan summation algorithm reduces the numerical error obtained with standard
+        sequential sum.
+
+    */
+    template<typename Args>
+    sum_kahan_impl(Args const & args)
+      : sum(args[parameter::keyword<Tag>::get() | Sample()]),
+        compensation(boost::numeric_cast<Sample>(0.0))
+    {
+    }
+
+    template<typename Args>
+    void 
+#if BOOST_ACCUMULATORS_GCC_VERSION > 40305
+    __attribute__((optimize("no-associative-math")))
+#endif
+    operator ()(Args const & args)
+    {
+        const Sample myTmp1 = args[parameter::keyword<Tag>::get()] - this->compensation;
+        const Sample myTmp2 = this->sum + myTmp1;
+        this->compensation = (myTmp2 - this->sum) - myTmp1;
+        this->sum = myTmp2;
+    }
+
+    result_type result(dont_care) const
+    {
+      return this->sum;
+    }
+
+private:
+    Sample sum;
+    Sample compensation;
+};
+
+#if _MSC_VER > 1400
+# pragma float_control(pop)
+#endif
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::sum_kahan
+// tag::sum_of_weights_kahan
+// tag::sum_of_variates_kahan
+//
+namespace tag
+{
+
+    struct sum_kahan
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef impl::sum_kahan_impl< mpl::_1, tag::sample > impl;
+    };
+
+    struct sum_of_weights_kahan
+      : depends_on<>
+    {
+        typedef mpl::true_ is_weight_accumulator;
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::sum_kahan_impl<mpl::_2, tag::weight> impl;
+    };
+
+    template<typename VariateType, typename VariateTag>
+    struct sum_of_variates_kahan
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef mpl::always<accumulators::impl::sum_kahan_impl<VariateType, VariateTag> > impl;
+    };
+
+} // namespace tag
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::sum_kahan
+// extract::sum_of_weights_kahan
+// extract::sum_of_variates_kahan
+//
+namespace extract
+{
+    extractor<tag::sum_kahan> const sum_kahan = {};
+    extractor<tag::sum_of_weights_kahan> const sum_of_weights_kahan = {};
+    extractor<tag::abstract_sum_of_variates> const sum_of_variates_kahan = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(sum_kahan)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(sum_of_weights_kahan)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(sum_of_variates_kahan)
+} // namespace extract
+
+using extract::sum_kahan;
+using extract::sum_of_weights_kahan;
+using extract::sum_of_variates_kahan;
+
+// sum(kahan) -> sum_kahan
+template<>
+struct as_feature<tag::sum(kahan)>
+{
+    typedef tag::sum_kahan type;
+};
+
+// sum_of_weights(kahan) -> sum_of_weights_kahan
+template<>
+struct as_feature<tag::sum_of_weights(kahan)>
+{
+    typedef tag::sum_of_weights_kahan type;
+};
+
+// So that sum_kahan can be automatically substituted with
+// weighted_sum_kahan when the weight parameter is non-void.
+template<>
+struct as_weighted_feature<tag::sum_kahan>
+{
+    typedef tag::weighted_sum_kahan type;
+};
+
+template<>
+struct feature_of<tag::weighted_sum_kahan>
+  : feature_of<tag::sum>
+{};
+
+// for the purposes of feature-based dependency resolution,
+// sum_kahan provides the same feature as sum
+template<>
+struct feature_of<tag::sum_kahan>
+  : feature_of<tag::sum>
+{
+};
+
+// for the purposes of feature-based dependency resolution,
+// sum_of_weights_kahan provides the same feature as sum_of_weights
+template<>
+struct feature_of<tag::sum_of_weights_kahan>
+  : feature_of<tag::sum_of_weights>
+{
+};
+
+template<typename VariateType, typename VariateTag>
+struct feature_of<tag::sum_of_variates_kahan<VariateType, VariateTag> >
+  : feature_of<tag::abstract_sum_of_variates>
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
+
diff --git a/boost/accumulators/statistics/tail.hpp b/boost/accumulators/statistics/tail.hpp
new file mode 100644
index 0000000..159a9b6
--- /dev/null
+++ b/boost/accumulators/statistics/tail.hpp
@@ -0,0 +1,334 @@
+///////////////////////////////////////////////////////////////////////////////
+// tail.hpp
+//
+//  Copyright 2005 Eric Niebler, Michael Gauckler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_TAIL_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_TAIL_HPP_EAN_28_10_2005
+
+#include <vector>
+#include <functional>
+#include <boost/assert.hpp>
+#include <boost/range.hpp>
+#include <boost/mpl/if.hpp>
+#include <boost/mpl/or.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/iterator/reverse_iterator.hpp>
+#include <boost/iterator/permutation_iterator.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+
+namespace boost { namespace accumulators
+{
+///////////////////////////////////////////////////////////////////////////////
+// cache_size named parameters
+BOOST_PARAMETER_NESTED_KEYWORD(tag, right_tail_cache_size, cache_size)
+BOOST_PARAMETER_NESTED_KEYWORD(tag, left_tail_cache_size, cache_size)
+
+namespace detail
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // tail_range
+    /// INTERNAL ONLY
+    ///
+    template<typename ElementIterator, typename IndexIterator>
+    struct tail_range
+    {
+        typedef boost::iterator_range<
+            boost::reverse_iterator<boost::permutation_iterator<ElementIterator, IndexIterator> >
+        > type;
+    };
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // make_tail_range
+    /// INTERNAL ONLY
+    ///
+    template<typename ElementIterator, typename IndexIterator>
+    typename tail_range<ElementIterator, IndexIterator>::type
+    make_tail_range(ElementIterator elem_begin, IndexIterator index_begin, IndexIterator index_end)
+    {
+        return boost::make_iterator_range(
+            boost::make_reverse_iterator(
+                boost::make_permutation_iterator(elem_begin, index_end)
+            )
+          , boost::make_reverse_iterator(
+                boost::make_permutation_iterator(elem_begin, index_begin)
+            )
+        );
+    }
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // stat_assign_visitor
+    /// INTERNAL ONLY
+    ///
+    template<typename Args>
+    struct stat_assign_visitor
+    {
+        stat_assign_visitor(Args const &a, std::size_t i)
+          : args(a)
+          , index(i)
+        {
+        }
+
+        template<typename Stat>
+        void operator ()(Stat &stat) const
+        {
+            stat.assign(this->args, this->index);
+        }
+
+    private:
+        stat_assign_visitor &operator =(stat_assign_visitor const &);
+        Args const &args;
+        std::size_t index;
+    };
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // stat_assign
+    /// INTERNAL ONLY
+    ///
+    template<typename Args>
+    inline stat_assign_visitor<Args> const stat_assign(Args const &args, std::size_t index)
+    {
+        return stat_assign_visitor<Args>(args, index);
+    }
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // is_tail_variate_feature
+    /// INTERNAL ONLY
+    ///
+    template<typename Stat, typename LeftRight>
+    struct is_tail_variate_feature
+      : mpl::false_
+    {
+    };
+
+    /// INTERNAL ONLY
+    ///
+    template<typename VariateType, typename VariateTag, typename LeftRight>
+    struct is_tail_variate_feature<tag::tail_variate<VariateType, VariateTag, LeftRight>, LeftRight>
+      : mpl::true_
+    {
+    };
+
+    /// INTERNAL ONLY
+    ///
+    template<typename LeftRight>
+    struct is_tail_variate_feature<tag::tail_weights<LeftRight>, LeftRight>
+      : mpl::true_
+    {
+    };
+
+} // namespace detail
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // tail_impl
+    template<typename Sample, typename LeftRight>
+    struct tail_impl
+      : accumulator_base
+    {
+        // LeftRight must be either right or left
+        BOOST_MPL_ASSERT((
+            mpl::or_<is_same<LeftRight, right>, is_same<LeftRight, left> >
+        ));
+
+        typedef
+            typename mpl::if_<
+                is_same<LeftRight, right>
+              , numeric::functional::greater<Sample const, Sample const>
+              , numeric::functional::less<Sample const, Sample const>
+            >::type
+        predicate_type;
+
+        // for boost::result_of
+        typedef typename detail::tail_range<
+            typename std::vector<Sample>::const_iterator
+          , std::vector<std::size_t>::iterator
+        >::type result_type;
+
+        template<typename Args>
+        tail_impl(Args const &args)
+          : is_sorted(false)
+          , indices()
+          , samples(args[tag::tail<LeftRight>::cache_size], args[sample | Sample()])
+        {
+            this->indices.reserve(this->samples.size());
+        }
+
+        tail_impl(tail_impl const &that)
+          : is_sorted(that.is_sorted)
+          , indices(that.indices)
+          , samples(that.samples)
+        {
+            this->indices.reserve(this->samples.size());
+        }
+
+        // This just stores the heap and the samples.
+        // In operator()() below, if we are adding a new sample
+        // to the sample cache, we force all the
+        // tail_variates to update also. (It's not
+        // good enough to wait for the accumulator_set to do it
+        // for us because then information about whether a sample
+        // was stored and where is lost, and would need to be
+        // queried at runtime, which would be slow.) This is
+        // implemented as a filtered visitation over the stats,
+        // which we can access because args[accumulator] gives us
+        // all the stats.
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            if(this->indices.size() < this->samples.size())
+            {
+                this->indices.push_back(this->indices.size());
+                this->assign(args, this->indices.back());
+            }
+            else if(predicate_type()(args[sample], this->samples[this->indices[0]]))
+            {
+                std::pop_heap(this->indices.begin(), this->indices.end(), indirect_cmp(this->samples));
+                this->assign(args, this->indices.back());
+            }
+        }
+
+        result_type result(dont_care) const
+        {
+            if(!this->is_sorted)
+            {
+                // Must use the same predicate here as in push_heap/pop_heap above.
+                std::sort_heap(this->indices.begin(), this->indices.end(), indirect_cmp(this->samples));
+                // sort_heap puts elements in reverse order. Calling std::reverse
+                // turns the sorted sequence back into a valid heap.
+                std::reverse(this->indices.begin(), this->indices.end());
+                this->is_sorted = true;
+            }
+
+            return detail::make_tail_range(
+                this->samples.begin()
+              , this->indices.begin()
+              , this->indices.end()
+            );
+        }
+
+    private:
+
+        struct is_tail_variate
+        {
+            template<typename T>
+            struct apply
+              : detail::is_tail_variate_feature<
+                    typename detail::feature_tag<T>::type
+                  , LeftRight
+                >
+            {};
+        };
+
+        template<typename Args>
+        void assign(Args const &args, std::size_t index)
+        {
+            BOOST_ASSERT(index < this->samples.size());
+            this->samples[index] = args[sample];
+            std::push_heap(this->indices.begin(), this->indices.end(), indirect_cmp(this->samples));
+            this->is_sorted = false;
+            // Tell the tail variates to store their values also
+            args[accumulator].template visit_if<is_tail_variate>(detail::stat_assign(args, index));
+        }
+
+        ///////////////////////////////////////////////////////////////////////////////
+        //
+        struct indirect_cmp
+          : std::binary_function<std::size_t, std::size_t, bool>
+        {
+            indirect_cmp(std::vector<Sample> const &s)
+              : samples(s)
+            {
+            }
+
+            bool operator ()(std::size_t left, std::size_t right) const
+            {
+                return predicate_type()(this->samples[left], this->samples[right]);
+            }
+
+        private:
+            indirect_cmp &operator =(indirect_cmp const &);
+            std::vector<Sample> const &samples;
+        };
+
+        mutable bool is_sorted;
+        mutable std::vector<std::size_t> indices;
+        std::vector<Sample> samples;
+    };
+
+} // namespace impl
+
+// TODO The templatized tag::tail below should inherit from the correct named parameter.
+// The following lines provide a workaround, but there must be a better way of doing this.
+template<typename T>
+struct tail_cache_size_named_arg
+{
+};
+template<>
+struct tail_cache_size_named_arg<left>
+  : tag::left_tail_cache_size
+{
+};
+template<>
+struct tail_cache_size_named_arg<right>
+  : tag::right_tail_cache_size
+{
+};
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::tail<>
+//
+namespace tag
+{
+    template<typename LeftRight>
+    struct tail
+      : depends_on<>
+      , tail_cache_size_named_arg<LeftRight>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::tail_impl<mpl::_1, LeftRight> impl;
+
+        #ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
+        /// tag::tail<LeftRight>::cache_size named parameter
+        static boost::parameter::keyword<tail_cache_size_named_arg<LeftRight> > const cache_size;
+        #endif
+    };
+
+    struct abstract_tail
+      : depends_on<>
+    {
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::tail
+//
+namespace extract
+{
+    extractor<tag::abstract_tail> const tail = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(tail)
+}
+
+using extract::tail;
+
+template<typename LeftRight>
+struct feature_of<tag::tail<LeftRight> >
+  : feature_of<tag::abstract_tail>
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/tail_mean.hpp b/boost/accumulators/statistics/tail_mean.hpp
new file mode 100644
index 0000000..323eeb0
--- /dev/null
+++ b/boost/accumulators/statistics/tail_mean.hpp
@@ -0,0 +1,246 @@
+///////////////////////////////////////////////////////////////////////////////
+// tail_mean.hpp
+//
+//  Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_TAIL_MEAN_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_TAIL_MEAN_HPP_DE_01_01_2006
+
+#include <numeric>
+#include <vector>
+#include <limits>
+#include <functional>
+#include <sstream>
+#include <stdexcept>
+#include <boost/throw_exception.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/tail.hpp>
+#include <boost/accumulators/statistics/tail_quantile.hpp>
+#include <boost/accumulators/statistics/parameters/quantile_probability.hpp>
+
+#ifdef _MSC_VER
+# pragma warning(push)
+# pragma warning(disable: 4127) // conditional expression is constant
+#endif
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // coherent_tail_mean_impl
+    //
+    /**
+        @brief Estimation of the coherent tail mean based on order statistics (for both left and right tails)
+
+        The coherent tail mean \f$\widehat{CTM}_{n,\alpha}(X)\f$ is equal to the non-coherent tail mean \f$\widehat{NCTM}_{n,\alpha}(X)\f$
+        plus a correction term that ensures coherence in case of non-continuous distributions.
+
+        \f[
+            \widehat{CTM}_{n,\alpha}^{\mathrm{right}}(X) = \widehat{NCTM}_{n,\alpha}^{\mathrm{right}}(X) +
+            \frac{1}{\lceil n(1-\alpha)\rceil}\hat{q}_{n,\alpha}(X)\left(1 - \alpha - \frac{1}{n}\lceil n(1-\alpha)\rceil \right)
+        \f]
+
+        \f[
+            \widehat{CTM}_{n,\alpha}^{\mathrm{left}}(X) = \widehat{NCTM}_{n,\alpha}^{\mathrm{left}}(X) +
+            \frac{1}{\lceil n\alpha\rceil}\hat{q}_{n,\alpha}(X)\left(\alpha - \frac{1}{n}\lceil n\alpha\rceil \right)
+        \f]
+    */
+    template<typename Sample, typename LeftRight>
+    struct coherent_tail_mean_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type float_type;
+        // for boost::result_of
+        typedef float_type result_type;
+
+        coherent_tail_mean_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            std::size_t cnt = count(args);
+
+            std::size_t n = static_cast<std::size_t>(
+                std::ceil(
+                    cnt * ( ( is_same<LeftRight, left>::value ) ? args[quantile_probability] : 1. - args[quantile_probability] )
+                )
+            );
+
+            extractor<tag::non_coherent_tail_mean<LeftRight> > const some_non_coherent_tail_mean = {};
+
+            return some_non_coherent_tail_mean(args)
+                 + numeric::average(quantile(args), n)
+                 * (
+                     ( is_same<LeftRight, left>::value ) ? args[quantile_probability] : 1. - args[quantile_probability]
+                     - numeric::average(n, count(args))
+                   );
+        }
+    };
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // non_coherent_tail_mean_impl
+    //
+    /**
+        @brief Estimation of the (non-coherent) tail mean based on order statistics (for both left and right tails)
+
+        An estimation of the non-coherent tail mean \f$\widehat{NCTM}_{n,\alpha}(X)\f$ is given by the mean of the
+        \f$\lceil n\alpha\rceil\f$ smallest samples (left tail) or the mean of the  \f$\lceil n(1-\alpha)\rceil\f$
+        largest samples (right tail), \f$n\f$ being the total number of samples and \f$\alpha\f$ the quantile level:
+
+        \f[
+            \widehat{NCTM}_{n,\alpha}^{\mathrm{right}}(X) = \frac{1}{\lceil n(1-\alpha)\rceil} \sum_{i=\lceil \alpha n \rceil}^n X_{i:n}
+        \f]
+
+        \f[
+            \widehat{NCTM}_{n,\alpha}^{\mathrm{left}}(X) = \frac{1}{\lceil n\alpha\rceil} \sum_{i=1}^{\lceil \alpha n \rceil} X_{i:n}
+        \f]
+
+        It thus requires the caching of at least the \f$\lceil n\alpha\rceil\f$ smallest or the \f$\lceil n(1-\alpha)\rceil\f$
+        largest samples.
+
+        @param quantile_probability
+    */
+    template<typename Sample, typename LeftRight>
+    struct non_coherent_tail_mean_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type float_type;
+        // for boost::result_of
+        typedef float_type result_type;
+
+        non_coherent_tail_mean_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            std::size_t cnt = count(args);
+
+            std::size_t n = static_cast<std::size_t>(
+                std::ceil(
+                    cnt * ( ( is_same<LeftRight, left>::value ) ? args[quantile_probability] : 1. - args[quantile_probability] )
+                )
+            );
+
+            // If n is in a valid range, return result, otherwise return NaN or throw exception
+            if (n <= static_cast<std::size_t>(tail(args).size()))
+                return numeric::average(
+                    std::accumulate(
+                        tail(args).begin()
+                      , tail(args).begin() + n
+                      , Sample(0)
+                    )
+                  , n
+                );
+            else
+            {
+                if (std::numeric_limits<result_type>::has_quiet_NaN)
+                {
+                    return std::numeric_limits<result_type>::quiet_NaN();
+                }
+                else
+                {
+                    std::ostringstream msg;
+                    msg << "index n = " << n << " is not in valid range [0, " << tail(args).size() << ")";
+                    boost::throw_exception(std::runtime_error(msg.str()));
+                    return Sample(0);
+                }
+            }
+        }
+    };
+
+} // namespace impl
+
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::coherent_tail_mean<>
+// tag::non_coherent_tail_mean<>
+//
+namespace tag
+{
+    template<typename LeftRight>
+    struct coherent_tail_mean
+      : depends_on<count, quantile, non_coherent_tail_mean<LeftRight> >
+    {
+        typedef accumulators::impl::coherent_tail_mean_impl<mpl::_1, LeftRight> impl;
+    };
+
+    template<typename LeftRight>
+    struct non_coherent_tail_mean
+      : depends_on<count, tail<LeftRight> >
+    {
+        typedef accumulators::impl::non_coherent_tail_mean_impl<mpl::_1, LeftRight> impl;
+    };
+
+    struct abstract_non_coherent_tail_mean
+      : depends_on<>
+    {
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::non_coherent_tail_mean;
+// extract::coherent_tail_mean;
+//
+namespace extract
+{
+    extractor<tag::abstract_non_coherent_tail_mean> const non_coherent_tail_mean = {};
+    extractor<tag::tail_mean> const coherent_tail_mean = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(non_coherent_tail_mean)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(coherent_tail_mean)
+}
+
+using extract::non_coherent_tail_mean;
+using extract::coherent_tail_mean;
+
+// for the purposes of feature-based dependency resolution,
+// coherent_tail_mean<LeftRight> provides the same feature as tail_mean
+template<typename LeftRight>
+struct feature_of<tag::coherent_tail_mean<LeftRight> >
+  : feature_of<tag::tail_mean>
+{
+};
+
+template<typename LeftRight>
+struct feature_of<tag::non_coherent_tail_mean<LeftRight> >
+  : feature_of<tag::abstract_non_coherent_tail_mean>
+{
+};
+
+// So that non_coherent_tail_mean can be automatically substituted
+// with weighted_non_coherent_tail_mean when the weight parameter is non-void.
+template<typename LeftRight>
+struct as_weighted_feature<tag::non_coherent_tail_mean<LeftRight> >
+{
+    typedef tag::non_coherent_weighted_tail_mean<LeftRight> type;
+};
+
+template<typename LeftRight>
+struct feature_of<tag::non_coherent_weighted_tail_mean<LeftRight> >
+  : feature_of<tag::non_coherent_tail_mean<LeftRight> >
+{};
+
+// NOTE that non_coherent_tail_mean cannot be feature-grouped with tail_mean,
+// which is the base feature for coherent tail means, since (at least for
+// non-continuous distributions) non_coherent_tail_mean is a different measure!
+
+}} // namespace boost::accumulators
+
+#ifdef _MSC_VER
+# pragma warning(pop)
+#endif
+
+#endif
diff --git a/boost/accumulators/statistics/tail_quantile.hpp b/boost/accumulators/statistics/tail_quantile.hpp
new file mode 100644
index 0000000..d3b96b4
--- /dev/null
+++ b/boost/accumulators/statistics/tail_quantile.hpp
@@ -0,0 +1,158 @@
+///////////////////////////////////////////////////////////////////////////////
+// tail_quantile.hpp
+//
+//  Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_TAIL_QUANTILE_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_TAIL_QUANTILE_HPP_DE_01_01_2006
+
+#include <vector>
+#include <limits>
+#include <functional>
+#include <sstream>
+#include <stdexcept>
+#include <boost/config/no_tr1/cmath.hpp>             // For ceil
+#include <boost/throw_exception.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/mpl/if.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/tail.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/parameters/quantile_probability.hpp>
+
+#ifdef _MSC_VER
+# pragma warning(push)
+# pragma warning(disable: 4127) // conditional expression is constant
+#endif
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // tail_quantile_impl
+    //  Tail quantile estimation based on order statistics
+    /**
+        @brief Tail quantile estimation based on order statistics (for both left and right tails)
+
+        The estimation of a tail quantile \f$\hat{q}\f$ with level \f$\alpha\f$ based on order statistics requires the
+        chaching of at least the \f$\lceil n\alpha\rceil\f$ smallest or the \f$\lceil n(1-\alpha)\rceil\f$ largest samples,
+        \f$n\f$ being the total number of samples. The largest of the \f$\lceil n\alpha\rceil\f$ smallest samples or the
+        smallest of the \f$\lceil n(1-\alpha)\rceil\f$ largest samples provides an estimate for the quantile:
+
+        \f[
+            \hat{q}_{n,\alpha} = X_{\lceil \alpha n \rceil:n}
+        \f]
+
+        @param quantile_probability
+    */
+    template<typename Sample, typename LeftRight>
+    struct tail_quantile_impl
+      : accumulator_base
+    {
+        // for boost::result_of
+        typedef Sample result_type;
+
+        tail_quantile_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            std::size_t cnt = count(args);
+
+            std::size_t n = static_cast<std::size_t>(
+                std::ceil(
+                    cnt * ( ( is_same<LeftRight, left>::value ) ? args[quantile_probability] : 1. - args[quantile_probability] )
+                )
+            );
+
+            // If n is in a valid range, return result, otherwise return NaN or throw exception
+            if ( n < static_cast<std::size_t>(tail(args).size()))
+            {
+               // Note that the cached samples of the left are sorted in ascending order,
+               // whereas the samples of the right tail are sorted in descending order
+               return *(boost::begin(tail(args)) + n - 1);
+            }
+            else
+            {
+                if (std::numeric_limits<result_type>::has_quiet_NaN)
+                {
+                    return std::numeric_limits<result_type>::quiet_NaN();
+                }
+                else
+                {
+                    std::ostringstream msg;
+                    msg << "index n = " << n << " is not in valid range [0, " << tail(args).size() << ")";
+                    boost::throw_exception(std::runtime_error(msg.str()));
+                    return Sample(0);
+                }
+            }
+        }
+    };
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::tail_quantile<>
+//
+namespace tag
+{
+    template<typename LeftRight>
+    struct tail_quantile
+      : depends_on<count, tail<LeftRight> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::tail_quantile_impl<mpl::_1, LeftRight> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::tail_quantile
+//
+namespace extract
+{
+    extractor<tag::quantile> const tail_quantile = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(tail_quantile)
+}
+
+using extract::tail_quantile;
+
+// for the purposes of feature-based dependency resolution,
+// tail_quantile<LeftRight> provide the same feature as quantile
+template<typename LeftRight>
+struct feature_of<tag::tail_quantile<LeftRight> >
+  : feature_of<tag::quantile>
+{
+};
+
+// So that tail_quantile can be automatically substituted with
+// weighted_tail_quantile when the weight parameter is non-void.
+template<typename LeftRight>
+struct as_weighted_feature<tag::tail_quantile<LeftRight> >
+{
+    typedef tag::weighted_tail_quantile<LeftRight> type;
+};
+
+template<typename LeftRight>
+struct feature_of<tag::weighted_tail_quantile<LeftRight> >
+  : feature_of<tag::tail_quantile<LeftRight> >
+{};
+
+}} // namespace boost::accumulators
+
+#ifdef _MSC_VER
+# pragma warning(pop)
+#endif
+
+#endif
diff --git a/boost/accumulators/statistics/tail_variate.hpp b/boost/accumulators/statistics/tail_variate.hpp
new file mode 100644
index 0000000..a9fc7d2
--- /dev/null
+++ b/boost/accumulators/statistics/tail_variate.hpp
@@ -0,0 +1,141 @@
+///////////////////////////////////////////////////////////////////////////////
+// tail_variate.hpp
+//
+//  Copyright 2005 Eric Niebler, Michael Gauckler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_STAT_STATISTICS_TAIL_VARIATE_HPP_EAN_28_10_2005
+#define BOOST_STAT_STATISTICS_TAIL_VARIATE_HPP_EAN_28_10_2005
+
+#include <boost/range.hpp>
+#include <boost/mpl/always.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/iterator/reverse_iterator.hpp>
+#include <boost/iterator/permutation_iterator.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/tail.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // tail_variate_impl
+    template<typename VariateType, typename VariateTag, typename LeftRight>
+    struct tail_variate_impl
+      : accumulator_base
+    {
+        // for boost::result_of
+        typedef
+            typename detail::tail_range<
+                typename std::vector<VariateType>::const_iterator
+              , std::vector<std::size_t>::iterator
+            >::type
+        result_type;
+
+        template<typename Args>
+        tail_variate_impl(Args const &args)
+          : variates(args[tag::tail<LeftRight>::cache_size], args[parameter::keyword<VariateTag>::get() | VariateType()])
+        {
+        }
+
+        template<typename Args>
+        void assign(Args const &args, std::size_t index)
+        {
+            this->variates[index] = args[parameter::keyword<VariateTag>::get()];
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            // getting the order result causes the indices vector to be sorted.
+            extractor<tag::tail<LeftRight> > const some_tail = {};
+            return this->do_result(some_tail(args));
+        }
+
+    private:
+        template<typename TailRng>
+        result_type do_result(TailRng const &rng) const
+        {
+            return detail::make_tail_range(
+                this->variates.begin()
+              , rng.end().base().base()   // the index iterator
+              , rng.begin().base().base() // (begin and end reversed because these are reverse iterators)
+            );
+        }
+
+        std::vector<VariateType> variates;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::tail_variate<>
+//
+namespace tag
+{
+    template<typename VariateType, typename VariateTag, typename LeftRight>
+    struct tail_variate
+      : depends_on<tail<LeftRight> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef mpl::always<accumulators::impl::tail_variate_impl<VariateType, VariateTag, LeftRight> > impl;
+    };
+
+    struct abstract_tail_variate
+      : depends_on<>
+    {
+    };
+
+    template<typename LeftRight>
+    struct tail_weights
+      : depends_on<tail<LeftRight> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::tail_variate_impl<mpl::_2, tag::weight, LeftRight> impl;
+    };
+
+    struct abstract_tail_weights
+      : depends_on<>
+    {
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::tail_variate
+// extract::tail_weights
+//
+namespace extract
+{
+    extractor<tag::abstract_tail_variate> const tail_variate = {};
+    extractor<tag::abstract_tail_weights> const tail_weights = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(tail_variate)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(tail_weights)
+}
+
+using extract::tail_variate;
+using extract::tail_weights;
+
+template<typename VariateType, typename VariateTag, typename LeftRight>
+struct feature_of<tag::tail_variate<VariateType, VariateTag, LeftRight> >
+  : feature_of<tag::abstract_tail_variate>
+{
+};
+
+template<typename LeftRight>
+struct feature_of<tag::tail_weights<LeftRight> >
+{
+    typedef tag::abstract_tail_weights type;
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/tail_variate_means.hpp b/boost/accumulators/statistics/tail_variate_means.hpp
new file mode 100644
index 0000000..98991e2
--- /dev/null
+++ b/boost/accumulators/statistics/tail_variate_means.hpp
@@ -0,0 +1,258 @@
+///////////////////////////////////////////////////////////////////////////////
+// tail_variate_means.hpp
+//
+//  Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_TAIL_VARIATE_MEANS_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_TAIL_VARIATE_MEANS_HPP_DE_01_01_2006
+
+#include <numeric>
+#include <vector>
+#include <limits>
+#include <functional>
+#include <sstream>
+#include <stdexcept>
+#include <boost/throw_exception.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/tail.hpp>
+#include <boost/accumulators/statistics/tail_variate.hpp>
+#include <boost/accumulators/statistics/tail_mean.hpp>
+#include <boost/accumulators/statistics/parameters/quantile_probability.hpp>
+
+#ifdef _MSC_VER
+# pragma warning(push)
+# pragma warning(disable: 4127) // conditional expression is constant
+#endif
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    /**
+        @brief Estimation of the absolute and relative tail variate means (for both left and right tails)
+
+        For all \f$j\f$-th variates associated to the \f$\lceil n(1-\alpha)\rceil\f$ largest samples (or the
+        \f$\lceil n(1-\alpha)\rceil\f$ smallest samples in case of the left tail), the absolute tail means
+        \f$\widehat{ATM}_{n,\alpha}(X, j)\f$ are computed and returned as an iterator range. Alternatively,
+        the relative tail means \f$\widehat{RTM}_{n,\alpha}(X, j)\f$ are returned, which are the absolute
+        tail means normalized with the (non-coherent) sample tail mean \f$\widehat{NCTM}_{n,\alpha}(X)\f$.
+
+        \f[
+            \widehat{ATM}_{n,\alpha}^{\mathrm{right}}(X, j) =
+                \frac{1}{\lceil n(1-\alpha) \rceil}
+                \sum_{i=\lceil \alpha n \rceil}^n \xi_{j,i}
+        \f]
+
+        \f[
+            \widehat{ATM}_{n,\alpha}^{\mathrm{left}}(X, j) =
+                \frac{1}{\lceil n\alpha \rceil}
+                \sum_{i=1}^{\lceil n\alpha \rceil} \xi_{j,i}
+        \f]
+
+        \f[
+            \widehat{RTM}_{n,\alpha}^{\mathrm{right}}(X, j) =
+                \frac{\sum_{i=\lceil n\alpha \rceil}^n \xi_{j,i}}
+            {\lceil n(1-\alpha)\rceil\widehat{NCTM}_{n,\alpha}^{\mathrm{right}}(X)}
+        \f]
+
+        \f[
+            \widehat{RTM}_{n,\alpha}^{\mathrm{left}}(X, j) =
+                \frac{\sum_{i=1}^{\lceil n\alpha \rceil} \xi_{j,i}}
+            {\lceil n\alpha\rceil\widehat{NCTM}_{n,\alpha}^{\mathrm{left}}(X)}
+        \f]
+    */
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // tail_variate_means_impl
+    //  by default: absolute tail_variate_means
+    template<typename Sample, typename Impl, typename LeftRight, typename VariateTag>
+    struct tail_variate_means_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type float_type;
+        typedef std::vector<float_type> array_type;
+        // for boost::result_of
+        typedef iterator_range<typename array_type::iterator> result_type;
+
+        tail_variate_means_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            std::size_t cnt = count(args);
+
+            std::size_t n = static_cast<std::size_t>(
+                std::ceil(
+                    cnt * ( ( is_same<LeftRight, left>::value ) ? args[quantile_probability] : 1. - args[quantile_probability] )
+                )
+            );
+
+            std::size_t num_variates = tail_variate(args).begin()->size();
+
+            this->tail_means_.clear();
+            this->tail_means_.resize(num_variates, Sample(0));
+
+            // If n is in a valid range, return result, otherwise return NaN or throw exception
+            if (n < static_cast<std::size_t>(tail(args).size()))
+            {
+                this->tail_means_ = std::accumulate(
+                    tail_variate(args).begin()
+                  , tail_variate(args).begin() + n
+                  , this->tail_means_
+                  , numeric::plus
+                );
+
+                float_type factor = n * ( (is_same<Impl, relative>::value) ? non_coherent_tail_mean(args) : 1. );
+
+                std::transform(
+                    this->tail_means_.begin()
+                  , this->tail_means_.end()
+                  , this->tail_means_.begin()
+                  , std::bind2nd(std::divides<float_type>(), factor)
+                );
+            }
+            else
+            {
+                if (std::numeric_limits<float_type>::has_quiet_NaN)
+                {
+                    std::fill(
+                        this->tail_means_.begin()
+                      , this->tail_means_.end()
+                      , std::numeric_limits<float_type>::quiet_NaN()
+                    );
+                }
+                else
+                {
+                    std::ostringstream msg;
+                    msg << "index n = " << n << " is not in valid range [0, " << tail(args).size() << ")";
+                    boost::throw_exception(std::runtime_error(msg.str()));
+                }
+            }
+            return make_iterator_range(this->tail_means_);
+        }
+
+    private:
+
+        mutable array_type tail_means_;
+
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::absolute_tail_variate_means
+// tag::relative_tail_variate_means
+//
+namespace tag
+{
+    template<typename LeftRight, typename VariateType, typename VariateTag>
+    struct absolute_tail_variate_means
+      : depends_on<count, non_coherent_tail_mean<LeftRight>, tail_variate<VariateType, VariateTag, LeftRight> >
+    {
+        typedef accumulators::impl::tail_variate_means_impl<mpl::_1, absolute, LeftRight, VariateTag> impl;
+    };
+    template<typename LeftRight, typename VariateType, typename VariateTag>
+    struct relative_tail_variate_means
+      : depends_on<count, non_coherent_tail_mean<LeftRight>, tail_variate<VariateType, VariateTag, LeftRight> >
+    {
+        typedef accumulators::impl::tail_variate_means_impl<mpl::_1, relative, LeftRight, VariateTag> impl;
+    };
+    struct abstract_absolute_tail_variate_means
+      : depends_on<>
+    {
+    };
+    struct abstract_relative_tail_variate_means
+      : depends_on<>
+    {
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::tail_variate_means
+// extract::relative_tail_variate_means
+//
+namespace extract
+{
+    extractor<tag::abstract_absolute_tail_variate_means> const tail_variate_means = {};
+    extractor<tag::abstract_relative_tail_variate_means> const relative_tail_variate_means = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(tail_variate_means)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(relative_tail_variate_means)
+}
+
+using extract::tail_variate_means;
+using extract::relative_tail_variate_means;
+
+// tail_variate_means<LeftRight, VariateType, VariateTag>(absolute) -> absolute_tail_variate_means<LeftRight, VariateType, VariateTag>
+template<typename LeftRight, typename VariateType, typename VariateTag>
+struct as_feature<tag::tail_variate_means<LeftRight, VariateType, VariateTag>(absolute)>
+{
+    typedef tag::absolute_tail_variate_means<LeftRight, VariateType, VariateTag> type;
+};
+
+// tail_variate_means<LeftRight, VariateType, VariateTag>(relative) ->relative_tail_variate_means<LeftRight, VariateType, VariateTag>
+template<typename LeftRight, typename VariateType, typename VariateTag>
+struct as_feature<tag::tail_variate_means<LeftRight, VariateType, VariateTag>(relative)>
+{
+    typedef tag::relative_tail_variate_means<LeftRight, VariateType, VariateTag> type;
+};
+
+// Provides non-templatized extractor
+template<typename LeftRight, typename VariateType, typename VariateTag>
+struct feature_of<tag::absolute_tail_variate_means<LeftRight, VariateType, VariateTag> >
+  : feature_of<tag::abstract_absolute_tail_variate_means>
+{
+};
+
+// Provides non-templatized extractor
+template<typename LeftRight, typename VariateType, typename VariateTag>
+struct feature_of<tag::relative_tail_variate_means<LeftRight, VariateType, VariateTag> >
+  : feature_of<tag::abstract_relative_tail_variate_means>
+{
+};
+
+// So that absolute_tail_means can be automatically substituted
+// with absolute_weighted_tail_means when the weight parameter is non-void.
+template<typename LeftRight, typename VariateType, typename VariateTag>
+struct as_weighted_feature<tag::absolute_tail_variate_means<LeftRight, VariateType, VariateTag> >
+{
+    typedef tag::absolute_weighted_tail_variate_means<LeftRight, VariateType, VariateTag> type;
+};
+
+template<typename LeftRight, typename VariateType, typename VariateTag>
+struct feature_of<tag::absolute_weighted_tail_variate_means<LeftRight, VariateType, VariateTag> >
+  : feature_of<tag::absolute_tail_variate_means<LeftRight, VariateType, VariateTag> >
+{
+};
+
+// So that relative_tail_means can be automatically substituted
+// with relative_weighted_tail_means when the weight parameter is non-void.
+template<typename LeftRight, typename VariateType, typename VariateTag>
+struct as_weighted_feature<tag::relative_tail_variate_means<LeftRight, VariateType, VariateTag> >
+{
+    typedef tag::relative_weighted_tail_variate_means<LeftRight, VariateType, VariateTag> type;
+};
+
+template<typename LeftRight, typename VariateType, typename VariateTag>
+struct feature_of<tag::relative_weighted_tail_variate_means<LeftRight, VariateType, VariateTag> >
+  : feature_of<tag::relative_tail_variate_means<LeftRight, VariateType, VariateTag> >
+{
+};
+
+}} // namespace boost::accumulators
+
+#ifdef _MSC_VER
+# pragma warning(pop)
+#endif
+
+#endif
diff --git a/boost/accumulators/statistics/times2_iterator.hpp b/boost/accumulators/statistics/times2_iterator.hpp
new file mode 100644
index 0000000..211a46e
--- /dev/null
+++ b/boost/accumulators/statistics/times2_iterator.hpp
@@ -0,0 +1,58 @@
+///////////////////////////////////////////////////////////////////////////////
+// times2_iterator.hpp
+//
+//  Copyright 2006 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_TIMES2_ITERATOR_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_TIMES2_ITERATOR_HPP_DE_01_01_2006
+
+#include <functional>
+#include <boost/range/begin.hpp>
+#include <boost/range/end.hpp>
+#include <boost/range/iterator_range.hpp>
+#include <boost/iterator/transform_iterator.hpp>
+#include <boost/iterator/counting_iterator.hpp>
+#include <boost/iterator/permutation_iterator.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace detail
+{
+    typedef transform_iterator<
+        std::binder1st<std::multiplies<std::size_t> >
+      , counting_iterator<std::size_t>
+    > times2_iterator;
+
+    inline times2_iterator make_times2_iterator(std::size_t i)
+    {
+        return make_transform_iterator(
+            make_counting_iterator(i)
+          , std::bind1st(std::multiplies<std::size_t>(), 2)
+        );
+    }
+
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // lvalue_index_iterator
+    template<typename Base>
+    struct lvalue_index_iterator
+      : Base
+    {
+        lvalue_index_iterator(Base base)
+          : Base(base)
+        {
+        }
+
+        typename Base::reference operator [](typename Base::difference_type n) const
+        {
+            return *(*this + n);
+        }
+    };
+} // namespace detail
+
+}}
+
+#endif
diff --git a/boost/accumulators/statistics/variance.hpp b/boost/accumulators/statistics/variance.hpp
new file mode 100644
index 0000000..81807a2
--- /dev/null
+++ b/boost/accumulators/statistics/variance.hpp
@@ -0,0 +1,236 @@
+///////////////////////////////////////////////////////////////////////////////
+// variance.hpp
+//
+//  Copyright 2005 Daniel Egloff, Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_VARIANCE_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_VARIANCE_HPP_EAN_28_10_2005
+
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/sum.hpp>
+#include <boost/accumulators/statistics/mean.hpp>
+#include <boost/accumulators/statistics/moment.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    //! Lazy calculation of variance.
+    /*!
+        Default sample variance implementation based on the second moment \f$ M_n^{(2)} \f$ moment<2>, mean and count.
+        \f[
+            \sigma_n^2 = M_n^{(2)} - \mu_n^2.
+        \f]
+        where
+        \f[
+            \mu_n = \frac{1}{n} \sum_{i = 1}^n x_i.
+        \f]
+        is the estimate of the sample mean and \f$n\f$ is the number of samples.
+    */
+    template<typename Sample, typename MeanFeature>
+    struct lazy_variance_impl
+      : accumulator_base
+    {
+        // for boost::result_of
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type result_type;
+
+        lazy_variance_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            extractor<MeanFeature> mean;
+            result_type tmp = mean(args);
+            return accumulators::moment<2>(args) - tmp * tmp;
+        }
+    };
+
+    //! Iterative calculation of variance.
+    /*!
+        Iterative calculation of sample variance \f$\sigma_n^2\f$ according to the formula
+        \f[
+            \sigma_n^2 = \frac{1}{n} \sum_{i = 1}^n (x_i - \mu_n)^2 = \frac{n-1}{n} \sigma_{n-1}^2 + \frac{1}{n-1}(x_n - \mu_n)^2.
+        \f]
+        where
+        \f[
+            \mu_n = \frac{1}{n} \sum_{i = 1}^n x_i.
+        \f]
+        is the estimate of the sample mean and \f$n\f$ is the number of samples.
+
+        Note that the sample variance is not defined for \f$n <= 1\f$.
+
+        A simplification can be obtained by the approximate recursion
+        \f[
+            \sigma_n^2 \approx \frac{n-1}{n} \sigma_{n-1}^2 + \frac{1}{n}(x_n - \mu_n)^2.
+        \f]
+        because the difference
+        \f[
+            \left(\frac{1}{n-1} - \frac{1}{n}\right)(x_n - \mu_n)^2 = \frac{1}{n(n-1)}(x_n - \mu_n)^2.
+        \f]
+        converges to zero as \f$n \rightarrow \infty\f$. However, for small \f$ n \f$ the difference
+        can be non-negligible.
+    */
+    template<typename Sample, typename MeanFeature, typename Tag>
+    struct variance_impl
+      : accumulator_base
+    {
+        // for boost::result_of
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type result_type;
+
+        template<typename Args>
+        variance_impl(Args const &args)
+          : variance(numeric::average(args[sample | Sample()], numeric::one<std::size_t>::value))
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            std::size_t cnt = count(args);
+
+            if(cnt > 1)
+            {
+                extractor<MeanFeature> mean;
+                result_type tmp = args[parameter::keyword<Tag>::get()] - mean(args);
+                this->variance =
+                    numeric::average(this->variance * (cnt - 1), cnt)
+                  + numeric::average(tmp * tmp, cnt - 1);
+            }
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->variance;
+        }
+
+    private:
+        result_type variance;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::variance
+// tag::immediate_variance
+//
+namespace tag
+{
+    struct lazy_variance
+      : depends_on<moment<2>, mean>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::lazy_variance_impl<mpl::_1, mean> impl;
+    };
+
+    struct variance
+      : depends_on<count, immediate_mean>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::variance_impl<mpl::_1, mean, sample> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::lazy_variance
+// extract::variance
+//
+namespace extract
+{
+    extractor<tag::lazy_variance> const lazy_variance = {};
+    extractor<tag::variance> const variance = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(lazy_variance)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(variance)
+}
+
+using extract::lazy_variance;
+using extract::variance;
+
+// variance(lazy) -> lazy_variance
+template<>
+struct as_feature<tag::variance(lazy)>
+{
+    typedef tag::lazy_variance type;
+};
+
+// variance(immediate) -> variance
+template<>
+struct as_feature<tag::variance(immediate)>
+{
+    typedef tag::variance type;
+};
+
+// for the purposes of feature-based dependency resolution,
+// immediate_variance provides the same feature as variance
+template<>
+struct feature_of<tag::lazy_variance>
+  : feature_of<tag::variance>
+{
+};
+
+// So that variance can be automatically substituted with
+// weighted_variance when the weight parameter is non-void.
+template<>
+struct as_weighted_feature<tag::variance>
+{
+    typedef tag::weighted_variance type;
+};
+
+// for the purposes of feature-based dependency resolution,
+// weighted_variance provides the same feature as variance
+template<>
+struct feature_of<tag::weighted_variance>
+  : feature_of<tag::variance>
+{
+};
+
+// So that immediate_variance can be automatically substituted with
+// immediate_weighted_variance when the weight parameter is non-void.
+template<>
+struct as_weighted_feature<tag::lazy_variance>
+{
+    typedef tag::lazy_weighted_variance type;
+};
+
+// for the purposes of feature-based dependency resolution,
+// immediate_weighted_variance provides the same feature as immediate_variance
+template<>
+struct feature_of<tag::lazy_weighted_variance>
+  : feature_of<tag::lazy_variance>
+{
+};
+
+////////////////////////////////////////////////////////////////////////////
+//// droppable_accumulator<variance_impl>
+////  need to specialize droppable lazy variance to cache the result at the
+////  point the accumulator is dropped.
+///// INTERNAL ONLY
+/////
+//template<typename Sample, typename MeanFeature>
+//struct droppable_accumulator<impl::variance_impl<Sample, MeanFeature> >
+//  : droppable_accumulator_base<
+//        with_cached_result<impl::variance_impl<Sample, MeanFeature> >
+//    >
+//{
+//    template<typename Args>
+//    droppable_accumulator(Args const &args)
+//      : droppable_accumulator::base(args)
+//    {
+//    }
+//};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/variates/covariate.hpp b/boost/accumulators/statistics/variates/covariate.hpp
new file mode 100644
index 0000000..eeb4835
--- /dev/null
+++ b/boost/accumulators/statistics/variates/covariate.hpp
@@ -0,0 +1,21 @@
+///////////////////////////////////////////////////////////////////////////////
+// weight.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_VARIATES_COVARIATE_HPP_EAN_03_11_2005
+#define BOOST_ACCUMULATORS_STATISTICS_VARIATES_COVARIATE_HPP_EAN_03_11_2005
+
+#include <boost/parameter/keyword.hpp>
+
+namespace boost { namespace accumulators
+{
+
+BOOST_PARAMETER_KEYWORD(tag, covariate1)
+BOOST_PARAMETER_KEYWORD(tag, covariate2)
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_covariance.hpp b/boost/accumulators/statistics/weighted_covariance.hpp
new file mode 100644
index 0000000..83585b1
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_covariance.hpp
@@ -0,0 +1,133 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_covariance.hpp
+//
+//  Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_COVARIANCE_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_COVARIANCE_HPP_DE_01_01_2006
+
+#include <vector>
+#include <limits>
+#include <numeric>
+#include <functional>
+#include <complex>
+#include <boost/mpl/assert.hpp>
+#include <boost/mpl/bool.hpp>
+#include <boost/range.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/numeric/ublas/io.hpp>
+#include <boost/numeric/ublas/matrix.hpp>
+#include <boost/type_traits/is_scalar.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/covariance.hpp> // for numeric::outer_product() and type traits
+#include <boost/accumulators/statistics/weighted_mean.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_covariance_impl
+    //
+    /**
+        @brief Weighted Covariance Estimator
+
+        An iterative Monte Carlo estimator for the weighted covariance \f$\mathrm{Cov}(X,X')\f$, where \f$X\f$ is a sample
+        and \f$X'\f$ a variate, is given by:
+
+        \f[
+            \hat{c}_n = \frac{\bar{w}_n-w_n}{\bar{w}_n} \hat{c}_{n-1} + \frac{w_n}{\bar{w}_n-w_n}(X_n - \hat{\mu}_n)(X_n' - \hat{\mu}_n'),
+            \quad n\ge2,\quad\hat{c}_1 = 0,
+        \f]
+
+        \f$\hat{\mu}_n\f$ and \f$\hat{\mu}_n'\f$ being the weighted means of the samples and variates and
+        \f$\bar{w}_n\f$ the sum of the \f$n\f$ first weights \f$w_i\f$.
+    */
+    template<typename Sample, typename Weight, typename VariateType, typename VariateTag>
+    struct weighted_covariance_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Weight, typename numeric::functional::average<Sample, std::size_t>::result_type>::result_type weighted_sample_type;
+        typedef typename numeric::functional::multiplies<Weight, typename numeric::functional::average<VariateType, std::size_t>::result_type>::result_type weighted_variate_type;
+        // for boost::result_of
+        typedef typename numeric::functional::outer_product<weighted_sample_type, weighted_variate_type>::result_type result_type;
+
+        template<typename Args>
+        weighted_covariance_impl(Args const &args)
+          : cov_(
+                numeric::outer_product(
+                    numeric::average(args[sample | Sample()], (std::size_t)1)
+                      * numeric::one<Weight>::value
+                  , numeric::average(args[parameter::keyword<VariateTag>::get() | VariateType()], (std::size_t)1)
+                      * numeric::one<Weight>::value
+                )
+            )
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            std::size_t cnt = count(args);
+
+            if (cnt > 1)
+            {
+                extractor<tag::weighted_mean_of_variates<VariateType, VariateTag> > const some_weighted_mean_of_variates = {};
+
+                this->cov_ = this->cov_ * (sum_of_weights(args) - args[weight]) / sum_of_weights(args)
+                           + numeric::outer_product(
+                                 some_weighted_mean_of_variates(args) - args[parameter::keyword<VariateTag>::get()]
+                               , weighted_mean(args) - args[sample]
+                             ) * args[weight] / (sum_of_weights(args) - args[weight]);
+            }
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->cov_;
+        }
+
+    private:
+        result_type cov_;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_covariance
+//
+namespace tag
+{
+    template<typename VariateType, typename VariateTag>
+    struct weighted_covariance
+      : depends_on<count, sum_of_weights, weighted_mean, weighted_mean_of_variates<VariateType, VariateTag> >
+    {
+        typedef accumulators::impl::weighted_covariance_impl<mpl::_1, mpl::_2, VariateType, VariateTag> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_covariance
+//
+namespace extract
+{
+    extractor<tag::abstract_covariance> const weighted_covariance = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_covariance)
+}
+
+using extract::weighted_covariance;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_density.hpp b/boost/accumulators/statistics/weighted_density.hpp
new file mode 100644
index 0000000..68dc639
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_density.hpp
@@ -0,0 +1,221 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_density.hpp
+//
+//  Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_DENSITY_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_DENSITY_HPP_DE_01_01_2006
+
+#include <vector>
+#include <limits>
+#include <functional>
+#include <boost/range.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/sum.hpp>
+#include <boost/accumulators/statistics/max.hpp>
+#include <boost/accumulators/statistics/min.hpp>
+#include <boost/accumulators/statistics/density.hpp> // for named parameters density_cache_size and density_num_bins
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_density_impl
+    //  density histogram for weighted samples
+    /**
+        @brief Histogram density estimator for weighted samples
+
+        The histogram density estimator returns a histogram of the sample distribution. The positions and sizes of the bins
+        are determined using a specifiable number of cached samples (cache_size). The range between the minimum and the
+        maximum of the cached samples is subdivided into a specifiable number of bins (num_bins) of same size. Additionally,
+        an under- and an overflow bin is added to capture future under- and overflow samples. Once the bins are determined,
+        the cached samples and all subsequent samples are added to the correct bins. At the end, a range of std::pair is
+        returned, where each pair contains the position of the bin (lower bound) and the sum of the weights (normalized with the
+        sum of all weights).
+
+        @param density_cache_size Number of first samples used to determine min and max.
+        @param density_num_bins Number of bins (two additional bins collect under- and overflow samples).
+    */
+    template<typename Sample, typename Weight>
+    struct weighted_density_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Weight, std::size_t>::result_type float_type;
+        typedef std::vector<std::pair<float_type, float_type> > histogram_type;
+        typedef std::vector<float_type> array_type;
+        // for boost::result_of
+        typedef iterator_range<typename histogram_type::iterator> result_type;
+
+        template<typename Args>
+        weighted_density_impl(Args const &args)
+            : cache_size(args[density_cache_size])
+            , cache(cache_size)
+            , num_bins(args[density_num_bins])
+            , samples_in_bin(num_bins + 2, 0.)
+            , bin_positions(num_bins + 2)
+            , histogram(
+                num_bins + 2
+              , std::make_pair(
+                    numeric::average(args[sample | Sample()],(std::size_t)1)
+                  , numeric::average(args[sample | Sample()],(std::size_t)1)
+                )
+              )
+            , is_dirty(true)
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            this->is_dirty = true;
+
+            std::size_t cnt = count(args);
+
+            // Fill up cache with cache_size first samples
+            if (cnt <= this->cache_size)
+            {
+                this->cache[cnt - 1] = std::make_pair(args[sample], args[weight]);
+            }
+
+            // Once cache_size samples have been accumulated, create num_bins bins of same size between
+            // the minimum and maximum of the cached samples as well as an under- and an overflow bin.
+            // Store their lower bounds (bin_positions) and fill the bins with the cached samples (samples_in_bin).
+            if (cnt == this->cache_size)
+            {
+                float_type minimum = numeric::average((min)(args),(std::size_t)1);
+                float_type maximum = numeric::average((max)(args),(std::size_t)1);
+                float_type bin_size = numeric::average(maximum - minimum, this->num_bins);
+
+                // determine bin positions (their lower bounds)
+                for (std::size_t i = 0; i < this->num_bins + 2; ++i)
+                {
+                    this->bin_positions[i] = minimum + (i - 1.) * bin_size;
+                }
+
+                for (typename histogram_type::const_iterator iter = this->cache.begin(); iter != this->cache.end(); ++iter)
+                {
+                    if (iter->first < this->bin_positions[1])
+                    {
+                        this->samples_in_bin[0] += iter->second;
+                    }
+                    else if (iter->first >= this->bin_positions[this->num_bins + 1])
+                    {
+                        this->samples_in_bin[this->num_bins + 1] += iter->second;
+                    }
+                    else
+                    {
+                        typename array_type::iterator it = std::upper_bound(
+                            this->bin_positions.begin()
+                          , this->bin_positions.end()
+                          , iter->first
+                        );
+
+                        std::size_t d = std::distance(this->bin_positions.begin(), it);
+                        this->samples_in_bin[d - 1] += iter->second;
+                    }
+                }
+            }
+            // Add each subsequent sample to the correct bin
+            else if (cnt > this->cache_size)
+            {
+                if (args[sample] < this->bin_positions[1])
+                {
+                    this->samples_in_bin[0] += args[weight];
+                }
+                else if (args[sample] >= this->bin_positions[this->num_bins + 1])
+                {
+                    this->samples_in_bin[this->num_bins + 1] += args[weight];
+                }
+                else
+                {
+                    typename array_type::iterator it = std::upper_bound(
+                        this->bin_positions.begin()
+                      , this->bin_positions.end()
+                      , args[sample]
+                    );
+
+                    std::size_t d = std::distance(this->bin_positions.begin(), it);
+                    this->samples_in_bin[d - 1] += args[weight];
+                }
+            }
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            if (this->is_dirty)
+            {
+                this->is_dirty = false;
+
+                // creates a vector of std::pair where each pair i holds
+                // the values bin_positions[i] (x-axis of histogram) and
+                // samples_in_bin[i] / cnt (y-axis of histogram).
+
+                for (std::size_t i = 0; i < this->num_bins + 2; ++i)
+                {
+                    this->histogram[i] = std::make_pair(this->bin_positions[i], numeric::average(this->samples_in_bin[i], sum_of_weights(args)));
+                }
+            }
+
+            // returns a range of pairs
+            return make_iterator_range(this->histogram);
+        }
+
+    private:
+        std::size_t            cache_size;      // number of cached samples
+        histogram_type         cache;           // cache to store the first cache_size samples with their weights as std::pair
+        std::size_t            num_bins;        // number of bins
+        array_type             samples_in_bin;  // number of samples in each bin
+        array_type             bin_positions;   // lower bounds of bins
+        mutable histogram_type histogram;       // histogram
+        mutable bool is_dirty;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_density
+//
+namespace tag
+{
+    struct weighted_density
+      : depends_on<count, sum_of_weights, min, max>
+      , density_cache_size
+      , density_num_bins
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::weighted_density_impl<mpl::_1, mpl::_2> impl;
+
+        #ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
+        static boost::parameter::keyword<density_cache_size> const cache_size;
+        static boost::parameter::keyword<density_num_bins> const num_bins;
+        #endif
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_density
+//
+namespace extract
+{
+    extractor<tag::density> const weighted_density = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_density)
+}
+
+using extract::weighted_density;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_extended_p_square.hpp b/boost/accumulators/statistics/weighted_extended_p_square.hpp
new file mode 100644
index 0000000..7d7f38c
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_extended_p_square.hpp
@@ -0,0 +1,290 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_extended_p_square.hpp
+//
+//  Copyright 2005 Daniel Egloff. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_EXTENDED_P_SQUARE_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_EXTENDED_P_SQUARE_HPP_DE_01_01_2006
+
+#include <vector>
+#include <functional>
+#include <boost/range/begin.hpp>
+#include <boost/range/end.hpp>
+#include <boost/range/iterator_range.hpp>
+#include <boost/iterator/transform_iterator.hpp>
+#include <boost/iterator/counting_iterator.hpp>
+#include <boost/iterator/permutation_iterator.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/sum.hpp>
+#include <boost/accumulators/statistics/times2_iterator.hpp>
+#include <boost/accumulators/statistics/extended_p_square.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_extended_p_square_impl
+    //  multiple quantile estimation with weighted samples
+    /**
+        @brief Multiple quantile estimation with the extended \f$P^2\f$ algorithm for weighted samples
+
+        This version of the extended \f$P^2\f$ algorithm extends the extended \f$P^2\f$ algorithm to
+        support weighted samples. The extended \f$P^2\f$ algorithm dynamically estimates several
+        quantiles without storing samples. Assume that \f$m\f$ quantiles
+        \f$\xi_{p_1}, \ldots, \xi_{p_m}\f$ are to be estimated. Instead of storing the whole sample
+        cumulative distribution, the algorithm maintains only \f$m+2\f$ principal markers and
+        \f$m+1\f$ middle markers, whose positions are updated with each sample and whose heights
+        are adjusted (if necessary) using a piecewise-parablic formula. The heights of the principal
+        markers are the current estimates of the quantiles and are returned as an iterator range.
+
+        For further details, see
+
+        K. E. E. Raatikainen, Simultaneous estimation of several quantiles, Simulation, Volume 49,
+        Number 4 (October), 1986, p. 159-164.
+
+        The extended \f$ P^2 \f$ algorithm generalizess the \f$ P^2 \f$ algorithm of
+
+        R. Jain and I. Chlamtac, The P^2 algorithmus for dynamic calculation of quantiles and
+        histograms without storing observations, Communications of the ACM,
+        Volume 28 (October), Number 10, 1985, p. 1076-1085.
+
+        @param extended_p_square_probabilities A vector of quantile probabilities.
+    */
+    template<typename Sample, typename Weight>
+    struct weighted_extended_p_square_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample;
+        typedef typename numeric::functional::average<weighted_sample, std::size_t>::result_type float_type;
+        typedef std::vector<float_type> array_type;
+        // for boost::result_of
+        typedef iterator_range<
+            detail::lvalue_index_iterator<
+                permutation_iterator<
+                    typename array_type::const_iterator
+                  , detail::times2_iterator
+                >
+            >
+        > result_type;
+
+        template<typename Args>
+        weighted_extended_p_square_impl(Args const &args)
+          : probabilities(
+                boost::begin(args[extended_p_square_probabilities])
+              , boost::end(args[extended_p_square_probabilities])
+            )
+          , heights(2 * probabilities.size() + 3)
+          , actual_positions(heights.size())
+          , desired_positions(heights.size())
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            std::size_t cnt = count(args);
+            std::size_t sample_cell = 1; // k
+            std::size_t num_quantiles = this->probabilities.size();
+
+            // m+2 principal markers and m+1 middle markers
+            std::size_t num_markers = 2 * num_quantiles + 3;
+
+            // first accumulate num_markers samples
+            if(cnt <= num_markers)
+            {
+                this->heights[cnt - 1] = args[sample];
+                this->actual_positions[cnt - 1] = args[weight];
+
+                // complete the initialization of heights (and actual_positions) by sorting
+                if(cnt == num_markers)
+                {
+                    // TODO: we need to sort the initial samples (in heights) in ascending order and
+                    // sort their weights (in actual_positions) the same way. The following lines do
+                    // it, but there must be a better and more efficient way of doing this.
+                    typename array_type::iterator it_begin, it_end, it_min;
+
+                    it_begin = this->heights.begin();
+                    it_end   = this->heights.end();
+
+                    std::size_t pos = 0;
+
+                    while (it_begin != it_end)
+                    {
+                        it_min = std::min_element(it_begin, it_end);
+                        std::size_t d = std::distance(it_begin, it_min);
+                        std::swap(*it_begin, *it_min);
+                        std::swap(this->actual_positions[pos], this->actual_positions[pos + d]);
+                        ++it_begin;
+                        ++pos;
+                    }
+
+                    // calculate correct initial actual positions
+                    for (std::size_t i = 1; i < num_markers; ++i)
+                    {
+                        actual_positions[i] += actual_positions[i - 1];
+                    }
+                }
+            }
+            else
+            {
+                if(args[sample] < this->heights[0])
+                {
+                    this->heights[0] = args[sample];
+                    this->actual_positions[0] = args[weight];
+                    sample_cell = 1;
+                }
+                else if(args[sample] >= this->heights[num_markers - 1])
+                {
+                    this->heights[num_markers - 1] = args[sample];
+                    sample_cell = num_markers - 1;
+                }
+                else
+                {
+                    // find cell k = sample_cell such that heights[k-1] <= sample < heights[k]
+
+                    typedef typename array_type::iterator iterator;
+                    iterator it = std::upper_bound(
+                        this->heights.begin()
+                      , this->heights.end()
+                      , args[sample]
+                    );
+
+                    sample_cell = std::distance(this->heights.begin(), it);
+                }
+
+                // update actual position of all markers above sample_cell
+                for(std::size_t i = sample_cell; i < num_markers; ++i)
+                {
+                    this->actual_positions[i] += args[weight];
+                }
+
+                // compute desired positions
+                {
+                    this->desired_positions[0] = this->actual_positions[0];
+                    this->desired_positions[num_markers - 1] = sum_of_weights(args);
+                    this->desired_positions[1] = (sum_of_weights(args) - this->actual_positions[0]) * probabilities[0]
+                                              / 2. + this->actual_positions[0];
+                    this->desired_positions[num_markers - 2] = (sum_of_weights(args) - this->actual_positions[0])
+                                                            * (probabilities[num_quantiles - 1] + 1.)
+                                                            / 2. + this->actual_positions[0];
+
+                    for (std::size_t i = 0; i < num_quantiles; ++i)
+                    {
+                        this->desired_positions[2 * i + 2] = (sum_of_weights(args) - this->actual_positions[0])
+                                                          * probabilities[i] + this->actual_positions[0];
+                    }
+
+                    for (std::size_t i = 1; i < num_quantiles; ++i)
+                    {
+                        this->desired_positions[2 * i + 1] = (sum_of_weights(args) - this->actual_positions[0])
+                                                      * (probabilities[i - 1] + probabilities[i])
+                                                      / 2. + this->actual_positions[0];
+                    }
+                }
+
+                // adjust heights and actual_positions of markers 1 to num_markers - 2 if necessary
+                for (std::size_t i = 1; i <= num_markers - 2; ++i)
+                {
+                    // offset to desired position
+                    float_type d = this->desired_positions[i] - this->actual_positions[i];
+
+                    // offset to next position
+                    float_type dp = this->actual_positions[i + 1] - this->actual_positions[i];
+
+                    // offset to previous position
+                    float_type dm = this->actual_positions[i - 1] - this->actual_positions[i];
+
+                    // height ds
+                    float_type hp = (this->heights[i + 1] - this->heights[i]) / dp;
+                    float_type hm = (this->heights[i - 1] - this->heights[i]) / dm;
+
+                    if((d >= 1 && dp > 1) || (d <= -1 && dm < -1))
+                    {
+                        short sign_d = static_cast<short>(d / std::abs(d));
+
+                        float_type h = this->heights[i] + sign_d / (dp - dm) * ((sign_d - dm)*hp + (dp - sign_d) * hm);
+
+                        // try adjusting heights[i] using p-squared formula
+                        if(this->heights[i - 1] < h && h < this->heights[i + 1])
+                        {
+                            this->heights[i] = h;
+                        }
+                        else
+                        {
+                            // use linear formula
+                            if(d > 0)
+                            {
+                                this->heights[i] += hp;
+                            }
+                            if(d < 0)
+                            {
+                                this->heights[i] -= hm;
+                            }
+                        }
+                        this->actual_positions[i] += sign_d;
+                    }
+                }
+            }
+        }
+
+        result_type result(dont_care) const
+        {
+            // for i in [1,probabilities.size()], return heights[i * 2]
+            detail::times2_iterator idx_begin = detail::make_times2_iterator(1);
+            detail::times2_iterator idx_end = detail::make_times2_iterator(this->probabilities.size() + 1);
+
+            return result_type(
+                make_permutation_iterator(this->heights.begin(), idx_begin)
+              , make_permutation_iterator(this->heights.begin(), idx_end)
+            );
+        }
+
+    private:
+        array_type probabilities;         // the quantile probabilities
+        array_type heights;               // q_i
+        array_type actual_positions;      // n_i
+        array_type desired_positions;     // d_i
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_extended_p_square
+//
+namespace tag
+{
+    struct weighted_extended_p_square
+      : depends_on<count, sum_of_weights>
+      , extended_p_square_probabilities
+    {
+        typedef accumulators::impl::weighted_extended_p_square_impl<mpl::_1, mpl::_2> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_extended_p_square
+//
+namespace extract
+{
+    extractor<tag::weighted_extended_p_square> const weighted_extended_p_square = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_extended_p_square)
+}
+
+using extract::weighted_extended_p_square;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_kurtosis.hpp b/boost/accumulators/statistics/weighted_kurtosis.hpp
new file mode 100644
index 0000000..d51db5c
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_kurtosis.hpp
@@ -0,0 +1,105 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_kurtosis.hpp
+//
+//  Copyright 2006 Olivier Gygi, Daniel Egloff. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_KURTOSIS_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_KURTOSIS_HPP_EAN_28_10_2005
+
+#include <limits>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/weighted_moment.hpp>
+#include <boost/accumulators/statistics/weighted_mean.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_kurtosis_impl
+    /**
+        @brief Kurtosis estimation for weighted samples
+
+        The kurtosis of a sample distribution is defined as the ratio of the 4th central moment and the square of the 2nd central
+        moment (the variance) of the samples, minus 3. The term \f$ -3 \f$ is added in order to ensure that the normal distribution
+        has zero kurtosis. The kurtosis can also be expressed by the simple moments:
+
+        \f[
+            \hat{g}_2 =
+                \frac
+                {\widehat{m}_n^{(4)}-4\widehat{m}_n^{(3)}\hat{\mu}_n+6\widehat{m}_n^{(2)}\hat{\mu}_n^2-3\hat{\mu}_n^4}
+                {\left(\widehat{m}_n^{(2)} - \hat{\mu}_n^{2}\right)^2} - 3,
+        \f]
+
+        where \f$ \widehat{m}_n^{(i)} \f$ are the \f$ i \f$-th moment and \f$ \hat{\mu}_n \f$ the mean (first moment) of the
+        \f$ n \f$ samples.
+
+        The kurtosis estimator for weighted samples is formally identical to the estimator for unweighted samples, except that
+        the weighted counterparts of all measures it depends on are to be taken.
+    */
+    template<typename Sample, typename Weight>
+    struct weighted_kurtosis_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample;
+        // for boost::result_of
+        typedef typename numeric::functional::average<weighted_sample, weighted_sample>::result_type result_type;
+
+        weighted_kurtosis_impl(dont_care)
+        {
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            return numeric::average(
+                        accumulators::weighted_moment<4>(args)
+                        - 4. * accumulators::weighted_moment<3>(args) * weighted_mean(args)
+                        + 6. * accumulators::weighted_moment<2>(args) * weighted_mean(args) * weighted_mean(args)
+                        - 3. * weighted_mean(args) * weighted_mean(args) * weighted_mean(args) * weighted_mean(args)
+                      , ( accumulators::weighted_moment<2>(args) - weighted_mean(args) * weighted_mean(args) )
+                        * ( accumulators::weighted_moment<2>(args) - weighted_mean(args) * weighted_mean(args) )
+                   ) - 3.;
+        }
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_kurtosis
+//
+namespace tag
+{
+    struct weighted_kurtosis
+      : depends_on<weighted_mean, weighted_moment<2>, weighted_moment<3>, weighted_moment<4> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::weighted_kurtosis_impl<mpl::_1, mpl::_2> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_kurtosis
+//
+namespace extract
+{
+    extractor<tag::weighted_kurtosis> const weighted_kurtosis = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_kurtosis)
+}
+
+using extract::weighted_kurtosis;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_mean.hpp b/boost/accumulators/statistics/weighted_mean.hpp
new file mode 100644
index 0000000..c8d6513
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_mean.hpp
@@ -0,0 +1,189 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_mean.hpp
+//
+//  Copyright 2006 Eric Niebler, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_MEAN_HPP_EAN_03_11_2005
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_MEAN_HPP_EAN_03_11_2005
+
+#include <boost/mpl/assert.hpp>
+#include <boost/mpl/eval_if.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/weights.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/sum.hpp>
+#include <boost/accumulators/statistics/mean.hpp>
+#include <boost/accumulators/statistics/weighted_sum.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_mean_impl
+    //      lazy, by default
+    template<typename Sample, typename Weight, typename Tag>
+    struct weighted_mean_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample;
+        // for boost::result_of
+        typedef typename numeric::functional::average<weighted_sample, Weight>::result_type result_type;
+
+        weighted_mean_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            typedef
+                typename mpl::if_<
+                    is_same<Tag, tag::sample>
+                  , tag::weighted_sum
+                  , tag::weighted_sum_of_variates<Sample, Tag>
+                >::type
+            weighted_sum_tag;
+
+            extractor<weighted_sum_tag> const some_weighted_sum = {};
+
+            return numeric::average(some_weighted_sum(args), sum_of_weights(args));
+        }
+    };
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // immediate_weighted_mean_impl
+    //      immediate
+    template<typename Sample, typename Weight, typename Tag>
+    struct immediate_weighted_mean_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample;
+        // for boost::result_of
+        typedef typename numeric::functional::average<weighted_sample, Weight>::result_type result_type;
+
+        template<typename Args>
+        immediate_weighted_mean_impl(Args const &args)
+          : mean(
+                numeric::average(
+                    args[parameter::keyword<Tag>::get() | Sample()]
+                      * numeric::one<Weight>::value
+                  , numeric::one<Weight>::value
+                )
+            )
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            // Matthias:
+            //  need to pass the argument pack since the weight might be an external
+            //  accumulator set passed as a named parameter
+            Weight w_sum = sum_of_weights(args);
+            Weight w = args[weight];
+            weighted_sample const &s = args[parameter::keyword<Tag>::get()] * w;
+            this->mean = numeric::average(this->mean * (w_sum - w) + s, w_sum);
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->mean;
+        }
+
+    private:
+        result_type mean;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_mean
+// tag::immediate_weighted_mean
+//
+namespace tag
+{
+    struct weighted_mean
+      : depends_on<sum_of_weights, weighted_sum>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::weighted_mean_impl<mpl::_1, mpl::_2, tag::sample> impl;
+    };
+    struct immediate_weighted_mean
+      : depends_on<sum_of_weights>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::immediate_weighted_mean_impl<mpl::_1, mpl::_2, tag::sample> impl;
+    };
+    template<typename VariateType, typename VariateTag>
+    struct weighted_mean_of_variates
+      : depends_on<sum_of_weights, weighted_sum_of_variates<VariateType, VariateTag> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::weighted_mean_impl<VariateType, mpl::_2, VariateTag> impl;
+    };
+    template<typename VariateType, typename VariateTag>
+    struct immediate_weighted_mean_of_variates
+      : depends_on<sum_of_weights>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::immediate_weighted_mean_impl<VariateType, mpl::_2, VariateTag> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_mean
+// extract::weighted_mean_of_variates
+//
+namespace extract
+{
+    extractor<tag::mean> const weighted_mean = {};
+    BOOST_ACCUMULATORS_DEFINE_EXTRACTOR(tag, weighted_mean_of_variates, (typename)(typename))
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_mean)
+}
+
+using extract::weighted_mean;
+using extract::weighted_mean_of_variates;
+
+// weighted_mean(lazy) -> weighted_mean
+template<>
+struct as_feature<tag::weighted_mean(lazy)>
+{
+    typedef tag::weighted_mean type;
+};
+
+// weighted_mean(immediate) -> immediate_weighted_mean
+template<>
+struct as_feature<tag::weighted_mean(immediate)>
+{
+    typedef tag::immediate_weighted_mean type;
+};
+
+// weighted_mean_of_variates<VariateType, VariateTag>(lazy) -> weighted_mean_of_variates<VariateType, VariateTag>
+template<typename VariateType, typename VariateTag>
+struct as_feature<tag::weighted_mean_of_variates<VariateType, VariateTag>(lazy)>
+{
+    typedef tag::weighted_mean_of_variates<VariateType, VariateTag> type;
+};
+
+// weighted_mean_of_variates<VariateType, VariateTag>(immediate) -> immediate_weighted_mean_of_variates<VariateType, VariateTag>
+template<typename VariateType, typename VariateTag>
+struct as_feature<tag::weighted_mean_of_variates<VariateType, VariateTag>(immediate)>
+{
+    typedef tag::immediate_weighted_mean_of_variates<VariateType, VariateTag> type;
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_median.hpp b/boost/accumulators/statistics/weighted_median.hpp
new file mode 100644
index 0000000..46880c8
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_median.hpp
@@ -0,0 +1,237 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_median.hpp
+//
+//  Copyright 2006 Eric Niebler, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_MEDIAN_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_MEDIAN_HPP_EAN_28_10_2005
+
+#include <boost/mpl/placeholders.hpp>
+#include <boost/range/iterator_range.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/median.hpp>
+#include <boost/accumulators/statistics/weighted_p_square_quantile.hpp>
+#include <boost/accumulators/statistics/weighted_density.hpp>
+#include <boost/accumulators/statistics/weighted_p_square_cumulative_distribution.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_median_impl
+    //
+    /**
+        @brief Median estimation for weighted samples based on the \f$P^2\f$ quantile estimator
+
+        The \f$P^2\f$ algorithm for weighted samples is invoked with a quantile probability of 0.5.
+    */
+    template<typename Sample>
+    struct weighted_median_impl
+      : accumulator_base
+    {
+        // for boost::result_of
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type result_type;
+
+        weighted_median_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            return weighted_p_square_quantile_for_median(args);
+        }
+    };
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // with_density_weighted_median_impl
+    //
+    /**
+        @brief Median estimation for weighted samples based on the density estimator
+
+        The algorithm determines the bin in which the \f$0.5*cnt\f$-th sample lies, \f$cnt\f$ being
+        the total number of samples. It returns the approximate horizontal position of this sample,
+        based on a linear interpolation inside the bin.
+    */
+    template<typename Sample>
+    struct with_density_weighted_median_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Sample, std::size_t>::result_type float_type;
+        typedef std::vector<std::pair<float_type, float_type> > histogram_type;
+        typedef iterator_range<typename histogram_type::iterator> range_type;
+        // for boost::result_of
+        typedef float_type result_type;
+
+        template<typename Args>
+        with_density_weighted_median_impl(Args const &args)
+          : sum(numeric::average(args[sample | Sample()], (std::size_t)1))
+          , is_dirty(true)
+        {
+        }
+
+        void operator ()(dont_care)
+        {
+            this->is_dirty = true;
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            if (this->is_dirty)
+            {
+                this->is_dirty = false;
+
+                std::size_t cnt = count(args);
+                range_type histogram = weighted_density(args);
+                typename range_type::iterator it = histogram.begin();
+                while (this->sum < 0.5 * cnt)
+                {
+                    this->sum += it->second * cnt;
+                    ++it;
+                }
+                --it;
+                float_type over = numeric::average(this->sum - 0.5 * cnt, it->second * cnt);
+                this->median = it->first * over + (it + 1)->first * ( 1. - over );
+            }
+
+            return this->median;
+        }
+
+    private:
+        mutable float_type sum;
+        mutable bool is_dirty;
+        mutable float_type median;
+    };
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // with_p_square_cumulative_distribution_weighted_median_impl
+    //
+    /**
+        @brief Median estimation for weighted samples based on the \f$P^2\f$ cumulative distribution estimator
+
+        The algorithm determines the first (leftmost) bin with a height exceeding 0.5. It
+        returns the approximate horizontal position of where the cumulative distribution
+        equals 0.5, based on a linear interpolation inside the bin.
+    */
+    template<typename Sample, typename Weight>
+    struct with_p_square_cumulative_distribution_weighted_median_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample;
+        typedef typename numeric::functional::average<weighted_sample, std::size_t>::result_type float_type;
+        typedef std::vector<std::pair<float_type, float_type> > histogram_type;
+        typedef iterator_range<typename histogram_type::iterator> range_type;
+        // for boost::result_of
+        typedef float_type result_type;
+
+        with_p_square_cumulative_distribution_weighted_median_impl(dont_care)
+          : is_dirty(true)
+        {
+        }
+
+        void operator ()(dont_care)
+        {
+            this->is_dirty = true;
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            if (this->is_dirty)
+            {
+                this->is_dirty = false;
+
+                range_type histogram = weighted_p_square_cumulative_distribution(args);
+                typename range_type::iterator it = histogram.begin();
+                while (it->second < 0.5)
+                {
+                    ++it;
+                }
+                float_type over = numeric::average(it->second - 0.5, it->second - (it - 1)->second);
+                this->median = it->first * over + (it + 1)->first * ( 1. - over );
+            }
+
+            return this->median;
+        }
+    private:
+        mutable bool is_dirty;
+        mutable float_type median;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_median
+// tag::with_density_weighted_median
+// tag::with_p_square_cumulative_distribution_weighted_median
+//
+namespace tag
+{
+    struct weighted_median
+      : depends_on<weighted_p_square_quantile_for_median>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::weighted_median_impl<mpl::_1> impl;
+    };
+    struct with_density_weighted_median
+      : depends_on<count, weighted_density>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::with_density_weighted_median_impl<mpl::_1> impl;
+    };
+    struct with_p_square_cumulative_distribution_weighted_median
+      : depends_on<weighted_p_square_cumulative_distribution>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::with_p_square_cumulative_distribution_weighted_median_impl<mpl::_1, mpl::_2> impl;
+    };
+
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_median
+//
+namespace extract
+{
+    extractor<tag::median> const weighted_median = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_median)
+}
+
+using extract::weighted_median;
+// weighted_median(with_p_square_quantile) -> weighted_median
+template<>
+struct as_feature<tag::weighted_median(with_p_square_quantile)>
+{
+    typedef tag::weighted_median type;
+};
+
+// weighted_median(with_density) -> with_density_weighted_median
+template<>
+struct as_feature<tag::weighted_median(with_density)>
+{
+    typedef tag::with_density_weighted_median type;
+};
+
+// weighted_median(with_p_square_cumulative_distribution) -> with_p_square_cumulative_distribution_weighted_median
+template<>
+struct as_feature<tag::weighted_median(with_p_square_cumulative_distribution)>
+{
+    typedef tag::with_p_square_cumulative_distribution_weighted_median type;
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_moment.hpp b/boost/accumulators/statistics/weighted_moment.hpp
new file mode 100644
index 0000000..f49c362
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_moment.hpp
@@ -0,0 +1,96 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_moment.hpp
+//
+//  Copyright 2006, Eric Niebler, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_MOMENT_HPP_EAN_15_11_2005
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_MOMENT_HPP_EAN_15_11_2005
+
+#include <boost/config/no_tr1/cmath.hpp>
+#include <boost/mpl/int.hpp>
+#include <boost/mpl/assert.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/preprocessor/arithmetic/inc.hpp>
+#include <boost/preprocessor/repetition/repeat_from_to.hpp>
+#include <boost/preprocessor/repetition/enum_trailing_params.hpp>
+#include <boost/preprocessor/repetition/enum_trailing_binary_params.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/moment.hpp> // for pow()
+#include <boost/accumulators/statistics/sum.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_moment_impl
+    template<typename N, typename Sample, typename Weight>
+    struct weighted_moment_impl
+      : accumulator_base // TODO: also depends_on sum of powers
+    {
+        BOOST_MPL_ASSERT_RELATION(N::value, >, 0);
+        typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample;
+        // for boost::result_of
+        typedef typename numeric::functional::average<weighted_sample, Weight>::result_type result_type;
+
+        template<typename Args>
+        weighted_moment_impl(Args const &args)
+          : sum(args[sample | Sample()] * numeric::one<Weight>::value)
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            this->sum += args[weight] * numeric::pow(args[sample], N());
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            return numeric::average(this->sum, sum_of_weights(args));
+        }
+
+    private:
+        weighted_sample sum;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_moment
+//
+namespace tag
+{
+    template<int N>
+    struct weighted_moment
+      : depends_on<count, sum_of_weights>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::weighted_moment_impl<mpl::int_<N>, mpl::_1, mpl::_2> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_moment
+//
+namespace extract
+{
+    BOOST_ACCUMULATORS_DEFINE_EXTRACTOR(tag, weighted_moment, (int))
+}
+
+using extract::weighted_moment;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_p_square_cumulative_distribution.hpp b/boost/accumulators/statistics/weighted_p_square_cumulative_distribution.hpp
new file mode 100644
index 0000000..290f090
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_p_square_cumulative_distribution.hpp
@@ -0,0 +1,262 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_p_square_cumulative_distribution.hpp
+//
+//  Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_P_SQUARE_CUMULATIVE_DISTRIBUTION_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_P_SQUARE_CUMULATIVE_DISTRIBUTION_HPP_DE_01_01_2006
+
+#include <vector>
+#include <functional>
+#include <boost/parameter/keyword.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/range.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/sum.hpp>
+#include <boost/accumulators/statistics/p_square_cumulative_distribution.hpp> // for named parameter p_square_cumulative_distribution_num_cells
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_p_square_cumulative_distribution_impl
+    //  cumulative distribution calculation (as histogram)
+    /**
+        @brief Histogram calculation of the cumulative distribution with the \f$P^2\f$ algorithm for weighted samples
+
+        A histogram of the sample cumulative distribution is computed dynamically without storing samples
+        based on the \f$ P^2 \f$ algorithm for weighted samples. The returned histogram has a specifiable
+        amount (num_cells) equiprobable (and not equal-sized) cells.
+
+        Note that applying importance sampling results in regions to be more and other regions to be less
+        accurately estimated than without importance sampling, i.e., with unweighted samples.
+
+        For further details, see
+
+        R. Jain and I. Chlamtac, The P^2 algorithmus for dynamic calculation of quantiles and
+        histograms without storing observations, Communications of the ACM,
+        Volume 28 (October), Number 10, 1985, p. 1076-1085.
+
+        @param p_square_cumulative_distribution_num_cells
+    */
+    template<typename Sample, typename Weight>
+    struct weighted_p_square_cumulative_distribution_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample;
+        typedef typename numeric::functional::average<weighted_sample, std::size_t>::result_type float_type;
+        typedef std::vector<std::pair<float_type, float_type> > histogram_type;
+        typedef std::vector<float_type> array_type;
+        // for boost::result_of
+        typedef iterator_range<typename histogram_type::iterator> result_type;
+
+        template<typename Args>
+        weighted_p_square_cumulative_distribution_impl(Args const &args)
+          : num_cells(args[p_square_cumulative_distribution_num_cells])
+          , heights(num_cells + 1)
+          , actual_positions(num_cells + 1)
+          , desired_positions(num_cells + 1)
+          , histogram(num_cells + 1)
+          , is_dirty(true)
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            this->is_dirty = true;
+
+            std::size_t cnt = count(args);
+            std::size_t sample_cell = 1; // k
+            std::size_t b = this->num_cells;
+
+            // accumulate num_cells + 1 first samples
+            if (cnt <= b + 1)
+            {
+                this->heights[cnt - 1] = args[sample];
+                this->actual_positions[cnt - 1] = args[weight];
+
+                // complete the initialization of heights by sorting
+                if (cnt == b + 1)
+                {
+                    //std::sort(this->heights.begin(), this->heights.end());
+
+                    // TODO: we need to sort the initial samples (in heights) in ascending order and
+                    // sort their weights (in actual_positions) the same way. The following lines do
+                    // it, but there must be a better and more efficient way of doing this.
+                    typename array_type::iterator it_begin, it_end, it_min;
+
+                    it_begin = this->heights.begin();
+                    it_end   = this->heights.end();
+
+                    std::size_t pos = 0;
+
+                    while (it_begin != it_end)
+                    {
+                        it_min = std::min_element(it_begin, it_end);
+                        std::size_t d = std::distance(it_begin, it_min);
+                        std::swap(*it_begin, *it_min);
+                        std::swap(this->actual_positions[pos], this->actual_positions[pos + d]);
+                        ++it_begin;
+                        ++pos;
+                    }
+
+                    // calculate correct initial actual positions
+                    for (std::size_t i = 1; i < b; ++i)
+                    {
+                        this->actual_positions[i] += this->actual_positions[i - 1];
+                    }
+                }
+            }
+            else
+            {
+                // find cell k such that heights[k-1] <= args[sample] < heights[k] and adjust extreme values
+                if (args[sample] < this->heights[0])
+                {
+                    this->heights[0] = args[sample];
+                    this->actual_positions[0] = args[weight];
+                    sample_cell = 1;
+                }
+                else if (this->heights[b] <= args[sample])
+                {
+                    this->heights[b] = args[sample];
+                    sample_cell = b;
+                }
+                else
+                {
+                    typename array_type::iterator it;
+                    it = std::upper_bound(
+                        this->heights.begin()
+                      , this->heights.end()
+                      , args[sample]
+                    );
+
+                    sample_cell = std::distance(this->heights.begin(), it);
+                }
+
+                // increment positions of markers above sample_cell
+                for (std::size_t i = sample_cell; i < b + 1; ++i)
+                {
+                    this->actual_positions[i] += args[weight];
+                }
+
+                // determine desired marker positions
+                for (std::size_t i = 1; i < b + 1; ++i)
+                {
+                    this->desired_positions[i] = this->actual_positions[0]
+                                               + numeric::average((i-1) * (sum_of_weights(args) - this->actual_positions[0]), b);
+                }
+
+                // adjust heights of markers 2 to num_cells if necessary
+                for (std::size_t i = 1; i < b; ++i)
+                {
+                    // offset to desire position
+                    float_type d = this->desired_positions[i] - this->actual_positions[i];
+
+                    // offset to next position
+                    float_type dp = this->actual_positions[i + 1] - this->actual_positions[i];
+
+                    // offset to previous position
+                    float_type dm = this->actual_positions[i - 1] - this->actual_positions[i];
+
+                    // height ds
+                    float_type hp = (this->heights[i + 1] - this->heights[i]) / dp;
+                    float_type hm = (this->heights[i - 1] - this->heights[i]) / dm;
+
+                    if ( ( d >= 1. && dp > 1. ) || ( d <= -1. && dm < -1. ) )
+                    {
+                        short sign_d = static_cast<short>(d / std::abs(d));
+
+                        // try adjusting heights[i] using p-squared formula
+                        float_type h = this->heights[i] + sign_d / (dp - dm) * ( (sign_d - dm) * hp + (dp - sign_d) * hm );
+
+                        if ( this->heights[i - 1] < h && h < this->heights[i + 1] )
+                        {
+                            this->heights[i] = h;
+                        }
+                        else
+                        {
+                            // use linear formula
+                            if (d>0)
+                            {
+                                this->heights[i] += hp;
+                            }
+                            if (d<0)
+                            {
+                                this->heights[i] -= hm;
+                            }
+                        }
+                        this->actual_positions[i] += sign_d;
+                    }
+                }
+            }
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            if (this->is_dirty)
+            {
+                this->is_dirty = false;
+
+                // creates a vector of std::pair where each pair i holds
+                // the values heights[i] (x-axis of histogram) and
+                // actual_positions[i] / sum_of_weights (y-axis of histogram)
+
+                for (std::size_t i = 0; i < this->histogram.size(); ++i)
+                {
+                    this->histogram[i] = std::make_pair(this->heights[i], numeric::average(this->actual_positions[i], sum_of_weights(args)));
+                }
+            }
+
+            return make_iterator_range(this->histogram);
+        }
+
+    private:
+        std::size_t num_cells;            // number of cells b
+        array_type  heights;              // q_i
+        array_type  actual_positions;     // n_i
+        array_type  desired_positions;    // n'_i
+        mutable histogram_type histogram; // histogram
+        mutable bool is_dirty;
+    };
+
+} // namespace detail
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_p_square_cumulative_distribution
+//
+namespace tag
+{
+    struct weighted_p_square_cumulative_distribution
+      : depends_on<count, sum_of_weights>
+      , p_square_cumulative_distribution_num_cells
+    {
+        typedef accumulators::impl::weighted_p_square_cumulative_distribution_impl<mpl::_1, mpl::_2> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_p_square_cumulative_distribution
+//
+namespace extract
+{
+    extractor<tag::weighted_p_square_cumulative_distribution> const weighted_p_square_cumulative_distribution = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_p_square_cumulative_distribution)
+}
+
+using extract::weighted_p_square_cumulative_distribution;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_p_square_quantile.hpp b/boost/accumulators/statistics/weighted_p_square_quantile.hpp
new file mode 100644
index 0000000..4e0d4ef
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_p_square_quantile.hpp
@@ -0,0 +1,254 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_p_square_quantile.hpp
+//
+//  Copyright 2005 Daniel Egloff. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_P_SQUARE_QUANTILE_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_P_SQUARE_QUANTILE_HPP_DE_01_01_2006
+
+#include <functional>
+#include <boost/array.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/sum.hpp>
+#include <boost/accumulators/statistics/parameters/quantile_probability.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl {
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_p_square_quantile_impl
+    //  single quantile estimation with weighted samples
+    /**
+        @brief Single quantile estimation with the \f$P^2\f$ algorithm for weighted samples
+
+        This version of the \f$P^2\f$ algorithm extends the \f$P^2\f$ algorithm to support weighted samples.
+        The \f$P^2\f$ algorithm estimates a quantile dynamically without storing samples. Instead of
+        storing the whole sample cumulative distribution, only five points (markers) are stored. The heights
+        of these markers are the minimum and the maximum of the samples and the current estimates of the
+        \f$(p/2)\f$-, \f$p\f$ - and \f$(1+p)/2\f$ -quantiles. Their positions are equal to the number
+        of samples that are smaller or equal to the markers. Each time a new sample is added, the
+        positions of the markers are updated and if necessary their heights are adjusted using a piecewise-
+        parabolic formula.
+
+        For further details, see
+
+        R. Jain and I. Chlamtac, The P^2 algorithmus for dynamic calculation of quantiles and
+        histograms without storing observations, Communications of the ACM,
+        Volume 28 (October), Number 10, 1985, p. 1076-1085.
+
+        @param quantile_probability
+    */
+    template<typename Sample, typename Weight, typename Impl>
+    struct weighted_p_square_quantile_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample;
+        typedef typename numeric::functional::average<weighted_sample, std::size_t>::result_type float_type;
+        typedef array<float_type, 5> array_type;
+        // for boost::result_of
+        typedef float_type result_type;
+
+        template<typename Args>
+        weighted_p_square_quantile_impl(Args const &args)
+          : p(is_same<Impl, for_median>::value ? 0.5 : args[quantile_probability | 0.5])
+          , heights()
+          , actual_positions()
+          , desired_positions()
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            std::size_t cnt = count(args);
+
+            // accumulate 5 first samples
+            if (cnt <= 5)
+            {
+                this->heights[cnt - 1] = args[sample];
+
+                // In this initialization phase, actual_positions stores the weights of the
+                // inital samples that are needed at the end of the initialization phase to
+                // compute the correct initial positions of the markers.
+                this->actual_positions[cnt - 1] = args[weight];
+
+                // complete the initialization of heights and actual_positions by sorting
+                if (cnt == 5)
+                {
+                    // TODO: we need to sort the initial samples (in heights) in ascending order and
+                    // sort their weights (in actual_positions) the same way. The following lines do
+                    // it, but there must be a better and more efficient way of doing this.
+                    typename array_type::iterator it_begin, it_end, it_min;
+
+                    it_begin = this->heights.begin();
+                    it_end   = this->heights.end();
+
+                    std::size_t pos = 0;
+
+                    while (it_begin != it_end)
+                    {
+                        it_min = std::min_element(it_begin, it_end);
+                        std::size_t d = std::distance(it_begin, it_min);
+                        std::swap(*it_begin, *it_min);
+                        std::swap(this->actual_positions[pos], this->actual_positions[pos + d]);
+                        ++it_begin;
+                        ++pos;
+                    }
+
+                    // calculate correct initial actual positions
+                    for (std::size_t i = 1; i < 5; ++i)
+                    {
+                        this->actual_positions[i] += this->actual_positions[i - 1];
+                    }
+                }
+            }
+            else
+            {
+                std::size_t sample_cell = 1; // k
+
+                // find cell k such that heights[k-1] <= args[sample] < heights[k] and adjust extreme values
+                if (args[sample] < this->heights[0])
+                {
+                    this->heights[0] = args[sample];
+                    this->actual_positions[0] = args[weight];
+                    sample_cell = 1;
+                }
+                else if (this->heights[4] <= args[sample])
+                {
+                    this->heights[4] = args[sample];
+                    sample_cell = 4;
+                }
+                else
+                {
+                    typedef typename array_type::iterator iterator;
+                    iterator it = std::upper_bound(
+                        this->heights.begin()
+                      , this->heights.end()
+                      , args[sample]
+                    );
+
+                    sample_cell = std::distance(this->heights.begin(), it);
+                }
+
+                // increment positions of markers above sample_cell
+                for (std::size_t i = sample_cell; i < 5; ++i)
+                {
+                    this->actual_positions[i] += args[weight];
+                }
+
+                // update desired positions for all markers
+                this->desired_positions[0] = this->actual_positions[0];
+                this->desired_positions[1] = (sum_of_weights(args) - this->actual_positions[0])
+                                           * this->p/2. + this->actual_positions[0];
+                this->desired_positions[2] = (sum_of_weights(args) - this->actual_positions[0])
+                                           * this->p + this->actual_positions[0];
+                this->desired_positions[3] = (sum_of_weights(args) - this->actual_positions[0])
+                                           * (1. + this->p)/2. + this->actual_positions[0];
+                this->desired_positions[4] = sum_of_weights(args);
+
+                // adjust height and actual positions of markers 1 to 3 if necessary
+                for (std::size_t i = 1; i <= 3; ++i)
+                {
+                    // offset to desired positions
+                    float_type d = this->desired_positions[i] - this->actual_positions[i];
+
+                    // offset to next position
+                    float_type dp = this->actual_positions[i + 1] - this->actual_positions[i];
+
+                    // offset to previous position
+                    float_type dm = this->actual_positions[i - 1] - this->actual_positions[i];
+
+                    // height ds
+                    float_type hp = (this->heights[i + 1] - this->heights[i]) / dp;
+                    float_type hm = (this->heights[i - 1] - this->heights[i]) / dm;
+
+                    if ( ( d >= 1. && dp > 1. ) || ( d <= -1. && dm < -1. ) )
+                    {
+                        short sign_d = static_cast<short>(d / std::abs(d));
+
+                        // try adjusting heights[i] using p-squared formula
+                        float_type h = this->heights[i] + sign_d / (dp - dm) * ( (sign_d - dm) * hp + (dp - sign_d) * hm );
+
+                        if ( this->heights[i - 1] < h && h < this->heights[i + 1] )
+                        {
+                            this->heights[i] = h;
+                        }
+                        else
+                        {
+                            // use linear formula
+                            if (d>0)
+                            {
+                                this->heights[i] += hp;
+                            }
+                            if (d<0)
+                            {
+                                this->heights[i] -= hm;
+                            }
+                        }
+                        this->actual_positions[i] += sign_d;
+                    }
+                }
+            }
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->heights[2];
+        }
+
+    private:
+        float_type p;                    // the quantile probability p
+        array_type heights;              // q_i
+        array_type actual_positions;     // n_i
+        array_type desired_positions;    // n'_i
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_p_square_quantile
+//
+namespace tag
+{
+    struct weighted_p_square_quantile
+      : depends_on<count, sum_of_weights>
+    {
+        typedef accumulators::impl::weighted_p_square_quantile_impl<mpl::_1, mpl::_2, regular> impl;
+    };
+    struct weighted_p_square_quantile_for_median
+      : depends_on<count, sum_of_weights>
+    {
+        typedef accumulators::impl::weighted_p_square_quantile_impl<mpl::_1, mpl::_2, for_median> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_p_square_quantile
+// extract::weighted_p_square_quantile_for_median
+//
+namespace extract
+{
+    extractor<tag::weighted_p_square_quantile> const weighted_p_square_quantile = {};
+    extractor<tag::weighted_p_square_quantile_for_median> const weighted_p_square_quantile_for_median = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_p_square_quantile)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_p_square_quantile_for_median)
+}
+
+using extract::weighted_p_square_quantile;
+using extract::weighted_p_square_quantile_for_median;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_peaks_over_threshold.hpp b/boost/accumulators/statistics/weighted_peaks_over_threshold.hpp
new file mode 100644
index 0000000..6d3017b
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_peaks_over_threshold.hpp
@@ -0,0 +1,288 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_peaks_over_threshold.hpp
+//
+//  Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_PEAKS_OVER_THRESHOLD_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_PEAKS_OVER_THRESHOLD_HPP_DE_01_01_2006
+
+#include <vector>
+#include <limits>
+#include <numeric>
+#include <functional>
+#include <boost/range.hpp>
+#include <boost/mpl/if.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/tuple/tuple.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/parameters/quantile_probability.hpp>
+#include <boost/accumulators/statistics/peaks_over_threshold.hpp> // for named parameters pot_threshold_value and pot_threshold_probability
+#include <boost/accumulators/statistics/sum.hpp>
+#include <boost/accumulators/statistics/tail_variate.hpp>
+
+#ifdef _MSC_VER
+# pragma warning(push)
+# pragma warning(disable: 4127) // conditional expression is constant
+#endif
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_peaks_over_threshold_impl
+    //  works with an explicit threshold value and does not depend on order statistics of weighted samples
+    /**
+        @brief Weighted Peaks over Threshold Method for Weighted Quantile and Weighted Tail Mean Estimation
+
+        @sa peaks_over_threshold_impl
+
+        @param quantile_probability
+        @param pot_threshold_value
+    */
+    template<typename Sample, typename Weight, typename LeftRight>
+    struct weighted_peaks_over_threshold_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Weight, Sample>::result_type weighted_sample;
+        typedef typename numeric::functional::average<weighted_sample, std::size_t>::result_type float_type;
+        // for boost::result_of
+        typedef boost::tuple<float_type, float_type, float_type> result_type;
+
+        template<typename Args>
+        weighted_peaks_over_threshold_impl(Args const &args)
+          : sign_((is_same<LeftRight, left>::value) ? -1 : 1)
+          , mu_(sign_ * numeric::average(args[sample | Sample()], (std::size_t)1))
+          , sigma2_(numeric::average(args[sample | Sample()], (std::size_t)1))
+          , w_sum_(numeric::average(args[weight | Weight()], (std::size_t)1))
+          , threshold_(sign_ * args[pot_threshold_value])
+          , fit_parameters_(boost::make_tuple(0., 0., 0.))
+          , is_dirty_(true)
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            this->is_dirty_ = true;
+
+            if (this->sign_ * args[sample] > this->threshold_)
+            {
+                this->mu_ += args[weight] * args[sample];
+                this->sigma2_ += args[weight] * args[sample] * args[sample];
+                this->w_sum_ += args[weight];
+            }
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            if (this->is_dirty_)
+            {
+                this->is_dirty_ = false;
+
+                this->mu_ = this->sign_ * numeric::average(this->mu_, this->w_sum_);
+                this->sigma2_ = numeric::average(this->sigma2_, this->w_sum_);
+                this->sigma2_ -= this->mu_ * this->mu_;
+
+                float_type threshold_probability = numeric::average(sum_of_weights(args) - this->w_sum_, sum_of_weights(args));
+
+                float_type tmp = numeric::average(( this->mu_ - this->threshold_ )*( this->mu_ - this->threshold_ ), this->sigma2_);
+                float_type xi_hat = 0.5 * ( 1. - tmp );
+                float_type beta_hat = 0.5 * ( this->mu_ - this->threshold_ ) * ( 1. + tmp );
+                float_type beta_bar = beta_hat * std::pow(1. - threshold_probability, xi_hat);
+                float_type u_bar = this->threshold_ - beta_bar * ( std::pow(1. - threshold_probability, -xi_hat) - 1.)/xi_hat;
+                this->fit_parameters_ = boost::make_tuple(u_bar, beta_bar, xi_hat);
+            }
+
+            return this->fit_parameters_;
+        }
+
+    private:
+        short sign_;                         // for left tail fitting, mirror the extreme values
+        mutable float_type mu_;              // mean of samples above threshold
+        mutable float_type sigma2_;          // variance of samples above threshold
+        mutable float_type w_sum_;           // sum of weights of samples above threshold
+        float_type threshold_;
+        mutable result_type fit_parameters_; // boost::tuple that stores fit parameters
+        mutable bool is_dirty_;
+    };
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_peaks_over_threshold_prob_impl
+    //  determines threshold from a given threshold probability using order statistics
+    /**
+        @brief Peaks over Threshold Method for Quantile and Tail Mean Estimation
+
+        @sa weighted_peaks_over_threshold_impl
+
+        @param quantile_probability
+        @param pot_threshold_probability
+    */
+    template<typename Sample, typename Weight, typename LeftRight>
+    struct weighted_peaks_over_threshold_prob_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Weight, Sample>::result_type weighted_sample;
+        typedef typename numeric::functional::average<weighted_sample, std::size_t>::result_type float_type;
+        // for boost::result_of
+        typedef boost::tuple<float_type, float_type, float_type> result_type;
+
+        template<typename Args>
+        weighted_peaks_over_threshold_prob_impl(Args const &args)
+          : sign_((is_same<LeftRight, left>::value) ? -1 : 1)
+          , mu_(sign_ * numeric::average(args[sample | Sample()], (std::size_t)1))
+          , sigma2_(numeric::average(args[sample | Sample()], (std::size_t)1))
+          , threshold_probability_(args[pot_threshold_probability])
+          , fit_parameters_(boost::make_tuple(0., 0., 0.))
+          , is_dirty_(true)
+        {
+        }
+
+        void operator ()(dont_care)
+        {
+            this->is_dirty_ = true;
+        }
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            if (this->is_dirty_)
+            {
+                this->is_dirty_ = false;
+
+                float_type threshold = sum_of_weights(args)
+                             * ( ( is_same<LeftRight, left>::value ) ? this->threshold_probability_ : 1. - this->threshold_probability_ );
+
+                std::size_t n = 0;
+                Weight sum = Weight(0);
+
+                while (sum < threshold)
+                {
+                    if (n < static_cast<std::size_t>(tail_weights(args).size()))
+                    {
+                        mu_ += *(tail_weights(args).begin() + n) * *(tail(args).begin() + n);
+                        sigma2_ += *(tail_weights(args).begin() + n) * *(tail(args).begin() + n) * (*(tail(args).begin() + n));
+                        sum += *(tail_weights(args).begin() + n);
+                        n++;
+                    }
+                    else
+                    {
+                        if (std::numeric_limits<float_type>::has_quiet_NaN)
+                        {
+                            return boost::make_tuple(
+                                std::numeric_limits<float_type>::quiet_NaN()
+                              , std::numeric_limits<float_type>::quiet_NaN()
+                              , std::numeric_limits<float_type>::quiet_NaN()
+                            );
+                        }
+                        else
+                        {
+                            std::ostringstream msg;
+                            msg << "index n = " << n << " is not in valid range [0, " << tail(args).size() << ")";
+                            boost::throw_exception(std::runtime_error(msg.str()));
+                            return boost::make_tuple(Sample(0), Sample(0), Sample(0));
+                        }
+                    }
+                }
+
+                float_type u = *(tail(args).begin() + n - 1) * this->sign_;
+
+
+                this->mu_ = this->sign_ * numeric::average(this->mu_, sum);
+                this->sigma2_ = numeric::average(this->sigma2_, sum);
+                this->sigma2_ -= this->mu_ * this->mu_;
+
+                if (is_same<LeftRight, left>::value)
+                    this->threshold_probability_ = 1. - this->threshold_probability_;
+
+                float_type tmp = numeric::average(( this->mu_ - u )*( this->mu_ - u ), this->sigma2_);
+                float_type xi_hat = 0.5 * ( 1. - tmp );
+                float_type beta_hat = 0.5 * ( this->mu_ - u ) * ( 1. + tmp );
+                float_type beta_bar = beta_hat * std::pow(1. - threshold_probability_, xi_hat);
+                float_type u_bar = u - beta_bar * ( std::pow(1. - threshold_probability_, -xi_hat) - 1.)/xi_hat;
+                this->fit_parameters_ = boost::make_tuple(u_bar, beta_bar, xi_hat);
+
+            }
+
+            return this->fit_parameters_;
+        }
+
+    private:
+        short sign_;                                // for left tail fitting, mirror the extreme values
+        mutable float_type mu_;                     // mean of samples above threshold u
+        mutable float_type sigma2_;                 // variance of samples above threshold u
+        mutable float_type threshold_probability_;
+        mutable result_type fit_parameters_;        // boost::tuple that stores fit parameters
+        mutable bool is_dirty_;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_peaks_over_threshold
+//
+namespace tag
+{
+    template<typename LeftRight>
+    struct weighted_peaks_over_threshold
+      : depends_on<sum_of_weights>
+      , pot_threshold_value
+    {
+        /// INTERNAL ONLY
+        typedef accumulators::impl::weighted_peaks_over_threshold_impl<mpl::_1, mpl::_2, LeftRight> impl;
+    };
+
+    template<typename LeftRight>
+    struct weighted_peaks_over_threshold_prob
+      : depends_on<sum_of_weights, tail_weights<LeftRight> >
+      , pot_threshold_probability
+    {
+        /// INTERNAL ONLY
+        typedef accumulators::impl::weighted_peaks_over_threshold_prob_impl<mpl::_1, mpl::_2, LeftRight> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_peaks_over_threshold
+//
+namespace extract
+{
+    extractor<tag::abstract_peaks_over_threshold> const weighted_peaks_over_threshold = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_peaks_over_threshold)
+}
+
+using extract::weighted_peaks_over_threshold;
+
+// weighted_peaks_over_threshold<LeftRight>(with_threshold_value) -> weighted_peaks_over_threshold<LeftRight>
+template<typename LeftRight>
+struct as_feature<tag::weighted_peaks_over_threshold<LeftRight>(with_threshold_value)>
+{
+    typedef tag::weighted_peaks_over_threshold<LeftRight> type;
+};
+
+// weighted_peaks_over_threshold<LeftRight>(with_threshold_probability) -> weighted_peaks_over_threshold_prob<LeftRight>
+template<typename LeftRight>
+struct as_feature<tag::weighted_peaks_over_threshold<LeftRight>(with_threshold_probability)>
+{
+    typedef tag::weighted_peaks_over_threshold_prob<LeftRight> type;
+};
+
+}} // namespace boost::accumulators
+
+#ifdef _MSC_VER
+# pragma warning(pop)
+#endif
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_skewness.hpp b/boost/accumulators/statistics/weighted_skewness.hpp
new file mode 100644
index 0000000..6ccbc45
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_skewness.hpp
@@ -0,0 +1,101 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_skewness.hpp
+//
+//  Copyright 2006 Olivier Gygi, Daniel Egloff. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_SKEWNESS_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_SKEWNESS_HPP_EAN_28_10_2005
+
+#include <limits>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/weighted_moment.hpp>
+#include <boost/accumulators/statistics/weighted_mean.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_skewness_impl
+    /**
+        @brief Skewness estimation for weighted samples
+
+        The skewness of a sample distribution is defined as the ratio of the 3rd central moment and the \f$ 3/2 \f$-th power $
+        of the 2nd central moment (the variance) of the samples. The skewness can also be expressed by the simple moments:
+
+        \f[
+            \hat{g}_1 =
+                \frac
+                {\widehat{m}_n^{(3)}-3\widehat{m}_n^{(2)}\hat{\mu}_n+2\hat{\mu}_n^3}
+                {\left(\widehat{m}_n^{(2)} - \hat{\mu}_n^{2}\right)^{3/2}}
+        \f]
+
+        where \f$ \widehat{m}_n^{(i)} \f$ are the \f$ i \f$-th moment and \f$ \hat{\mu}_n \f$ the mean (first moment) of the
+        \f$ n \f$ samples.
+
+        The skewness estimator for weighted samples is formally identical to the estimator for unweighted samples, except that
+        the weighted counterparts of all measures it depends on are to be taken.
+    */
+    template<typename Sample, typename Weight>
+    struct weighted_skewness_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample;
+        // for boost::result_of
+        typedef typename numeric::functional::average<weighted_sample, weighted_sample>::result_type result_type;
+
+        weighted_skewness_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            return numeric::average(
+                        accumulators::weighted_moment<3>(args)
+                        - 3. * accumulators::weighted_moment<2>(args) * weighted_mean(args)
+                        + 2. * weighted_mean(args) * weighted_mean(args) * weighted_mean(args)
+                      , ( accumulators::weighted_moment<2>(args) - weighted_mean(args) * weighted_mean(args) )
+                      * std::sqrt( accumulators::weighted_moment<2>(args) - weighted_mean(args) * weighted_mean(args) )
+                   );
+        }
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_skewness
+//
+namespace tag
+{
+    struct weighted_skewness
+      : depends_on<weighted_mean, weighted_moment<2>, weighted_moment<3> >
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::weighted_skewness_impl<mpl::_1, mpl::_2> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_skewness
+//
+namespace extract
+{
+    extractor<tag::weighted_skewness> const weighted_skewness = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_skewness)
+}
+
+using extract::weighted_skewness;
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_sum.hpp b/boost/accumulators/statistics/weighted_sum.hpp
new file mode 100644
index 0000000..2715390
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_sum.hpp
@@ -0,0 +1,116 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_sum.hpp
+//
+//  Copyright 2006 Eric Niebler, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_SUM_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_SUM_HPP_EAN_28_10_2005
+
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/parameters/weight.hpp>
+#include <boost/accumulators/framework/accumulators/external_accumulator.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_sum_impl
+    template<typename Sample, typename Weight, typename Tag>
+    struct weighted_sum_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample;
+
+        // for boost::result_of
+        typedef weighted_sample result_type;
+
+        template<typename Args>
+        weighted_sum_impl(Args const &args)
+          : weighted_sum_(
+                args[parameter::keyword<Tag>::get() | Sample()]
+                  * numeric::one<Weight>::value
+            )
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            // what about overflow?
+            this->weighted_sum_ += args[parameter::keyword<Tag>::get()] * args[weight];
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->weighted_sum_;
+        }
+
+    private:
+
+        weighted_sample weighted_sum_;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_sum
+//
+namespace tag
+{
+    struct weighted_sum
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::weighted_sum_impl<mpl::_1, mpl::_2, tag::sample> impl;
+    };
+
+    template<typename VariateType, typename VariateTag>
+    struct weighted_sum_of_variates
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::weighted_sum_impl<VariateType, mpl::_2, VariateTag> impl;
+    };
+
+    struct abstract_weighted_sum_of_variates
+      : depends_on<>
+    {
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_sum
+//
+namespace extract
+{
+    extractor<tag::weighted_sum> const weighted_sum = {};
+    extractor<tag::abstract_weighted_sum_of_variates> const weighted_sum_of_variates = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_sum)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_sum_of_variates)
+}
+
+using extract::weighted_sum;
+using extract::weighted_sum_of_variates;
+
+template<typename VariateType, typename VariateTag>
+struct feature_of<tag::weighted_sum_of_variates<VariateType, VariateTag> >
+  : feature_of<tag::abstract_weighted_sum_of_variates>
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_sum_kahan.hpp b/boost/accumulators/statistics/weighted_sum_kahan.hpp
new file mode 100644
index 0000000..ad9b83d
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_sum_kahan.hpp
@@ -0,0 +1,138 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_sum_kahan.hpp
+//
+//  Copyright 2011 Simon West. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_SUM_KAHAN_HPP_EAN_11_05_2011
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_SUM_KAHAN_HPP_EAN_11_05_2011
+
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/parameters/weight.hpp>
+#include <boost/accumulators/framework/accumulators/external_accumulator.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/weighted_sum.hpp>
+#include <boost/numeric/conversion/cast.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+#if _MSC_VER > 1400
+# pragma float_control(push)
+# pragma float_control(precise, on)
+#endif
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_sum_kahan_impl
+    template<typename Sample, typename Weight, typename Tag>
+    struct weighted_sum_kahan_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample;
+
+        // for boost::result_of
+        typedef weighted_sample result_type;
+
+        template<typename Args>
+        weighted_sum_kahan_impl(Args const &args)
+          : weighted_sum_(
+                args[parameter::keyword<Tag>::get() | Sample()] * numeric::one<Weight>::value),
+                compensation(boost::numeric_cast<weighted_sample>(0.0))
+        {
+        }
+
+        template<typename Args>
+        void 
+#if BOOST_ACCUMULATORS_GCC_VERSION > 40305
+        __attribute__((optimize("no-associative-math")))
+#endif
+        operator ()(Args const &args)
+        {
+            const weighted_sample myTmp1 = args[parameter::keyword<Tag>::get()] * args[weight] - this->compensation;
+            const weighted_sample myTmp2 = this->weighted_sum_ + myTmp1;
+            this->compensation = (myTmp2 - this->weighted_sum_) - myTmp1;
+            this->weighted_sum_ = myTmp2;
+
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->weighted_sum_;
+        }
+
+    private:
+        weighted_sample weighted_sum_;
+        weighted_sample compensation;
+    };
+
+#if _MSC_VER > 1400
+# pragma float_control(pop)
+#endif
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_sum_kahan
+// tag::weighted_sum_of_variates_kahan
+//
+namespace tag
+{
+    struct weighted_sum_kahan
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::weighted_sum_kahan_impl<mpl::_1, mpl::_2, tag::sample> impl;
+    };
+
+    template<typename VariateType, typename VariateTag>
+    struct weighted_sum_of_variates_kahan
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::weighted_sum_kahan_impl<VariateType, mpl::_2, VariateTag> impl;
+    };
+
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_sum_kahan
+// extract::weighted_sum_of_variates_kahan
+//
+namespace extract
+{
+    extractor<tag::weighted_sum_kahan> const weighted_sum_kahan = {};
+    extractor<tag::abstract_weighted_sum_of_variates> const weighted_sum_of_variates_kahan = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_sum_kahan)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_sum_of_variates_kahan)
+}
+
+using extract::weighted_sum_kahan;
+using extract::weighted_sum_of_variates_kahan;
+
+// weighted_sum(kahan) -> weighted_sum_kahan
+template<>
+struct as_feature<tag::weighted_sum(kahan)>
+{
+    typedef tag::weighted_sum_kahan type;
+};
+
+template<typename VariateType, typename VariateTag>
+struct feature_of<tag::weighted_sum_of_variates_kahan<VariateType, VariateTag> >
+  : feature_of<tag::abstract_weighted_sum_of_variates>
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_tail_mean.hpp b/boost/accumulators/statistics/weighted_tail_mean.hpp
new file mode 100644
index 0000000..5bdee8a
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_tail_mean.hpp
@@ -0,0 +1,169 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_tail_mean.hpp
+//
+//  Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_TAIL_MEAN_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_TAIL_MEAN_HPP_DE_01_01_2006
+
+#include <numeric>
+#include <vector>
+#include <limits>
+#include <functional>
+#include <sstream>
+#include <stdexcept>
+#include <boost/throw_exception.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/tail.hpp>
+#include <boost/accumulators/statistics/tail_mean.hpp>
+#include <boost/accumulators/statistics/parameters/quantile_probability.hpp>
+
+#ifdef _MSC_VER
+# pragma warning(push)
+# pragma warning(disable: 4127) // conditional expression is constant
+#endif
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // coherent_weighted_tail_mean_impl
+    //
+    // TODO
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // non_coherent_weighted_tail_mean_impl
+    //
+    /**
+        @brief Estimation of the (non-coherent) weighted tail mean based on order statistics (for both left and right tails)
+
+
+
+        An estimation of the non-coherent, weighted tail mean \f$\widehat{NCTM}_{n,\alpha}(X)\f$ is given by the weighted mean
+        of the
+
+        \f[
+            \lambda = \inf\left\{ l \left| \frac{1}{\bar{w}_n}\sum_{i=1}^{l} w_i \geq \alpha \right. \right\}
+        \f]
+
+        smallest samples (left tail) or the weighted mean of the
+
+        \f[
+            n + 1 - \rho = n + 1 - \sup\left\{ r \left| \frac{1}{\bar{w}_n}\sum_{i=r}^{n} w_i \geq (1 - \alpha) \right. \right\}
+        \f]
+
+        largest samples (right tail) above a quantile \f$\hat{q}_{\alpha}\f$ of level \f$\alpha\f$, \f$n\f$ being the total number of sample
+        and \f$\bar{w}_n\f$ the sum of all \f$n\f$ weights:
+
+        \f[
+            \widehat{NCTM}_{n,\alpha}^{\mathrm{left}}(X) = \frac{\sum_{i=1}^{\lambda} w_i X_{i:n}}{\sum_{i=1}^{\lambda} w_i},
+        \f]
+
+        \f[
+            \widehat{NCTM}_{n,\alpha}^{\mathrm{right}}(X) = \frac{\sum_{i=\rho}^n w_i X_{i:n}}{\sum_{i=\rho}^n w_i}.
+        \f]
+
+        @param quantile_probability
+    */
+    template<typename Sample, typename Weight, typename LeftRight>
+    struct non_coherent_weighted_tail_mean_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample;
+        typedef typename numeric::functional::average<Weight, std::size_t>::result_type float_type;
+        // for boost::result_of
+        typedef typename numeric::functional::average<weighted_sample, std::size_t>::result_type result_type;
+
+        non_coherent_weighted_tail_mean_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            float_type threshold = sum_of_weights(args)
+                             * ( ( is_same<LeftRight, left>::value ) ? args[quantile_probability] : 1. - args[quantile_probability] );
+
+            std::size_t n = 0;
+            Weight sum = Weight(0);
+
+            while (sum < threshold)
+            {
+                if (n < static_cast<std::size_t>(tail_weights(args).size()))
+                {
+                    sum += *(tail_weights(args).begin() + n);
+                    n++;
+                }
+                else
+                {
+                    if (std::numeric_limits<result_type>::has_quiet_NaN)
+                    {
+                        return std::numeric_limits<result_type>::quiet_NaN();
+                    }
+                    else
+                    {
+                        std::ostringstream msg;
+                        msg << "index n = " << n << " is not in valid range [0, " << tail(args).size() << ")";
+                        boost::throw_exception(std::runtime_error(msg.str()));
+                        return result_type(0);
+                    }
+                }
+            }
+
+            return numeric::average(
+                std::inner_product(
+                    tail(args).begin()
+                  , tail(args).begin() + n
+                  , tail_weights(args).begin()
+                  , weighted_sample(0)
+                )
+              , sum
+            );
+        }
+    };
+
+} // namespace impl
+
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::non_coherent_weighted_tail_mean<>
+//
+namespace tag
+{
+    template<typename LeftRight>
+    struct non_coherent_weighted_tail_mean
+      : depends_on<sum_of_weights, tail_weights<LeftRight> >
+    {
+        typedef accumulators::impl::non_coherent_weighted_tail_mean_impl<mpl::_1, mpl::_2, LeftRight> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::non_coherent_weighted_tail_mean;
+//
+namespace extract
+{
+    extractor<tag::abstract_non_coherent_tail_mean> const non_coherent_weighted_tail_mean = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(non_coherent_weighted_tail_mean)
+}
+
+using extract::non_coherent_weighted_tail_mean;
+
+}} // namespace boost::accumulators
+
+#ifdef _MSC_VER
+# pragma warning(pop)
+#endif
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_tail_quantile.hpp b/boost/accumulators/statistics/weighted_tail_quantile.hpp
new file mode 100644
index 0000000..88c32d1
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_tail_quantile.hpp
@@ -0,0 +1,146 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_tail_quantile.hpp
+//
+//  Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_TAIL_QUANTILE_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_TAIL_QUANTILE_HPP_DE_01_01_2006
+
+#include <vector>
+#include <limits>
+#include <functional>
+#include <sstream>
+#include <stdexcept>
+#include <boost/throw_exception.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/mpl/if.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/tail.hpp>
+#include <boost/accumulators/statistics/tail_quantile.hpp>
+#include <boost/accumulators/statistics/parameters/quantile_probability.hpp>
+
+#ifdef _MSC_VER
+# pragma warning(push)
+# pragma warning(disable: 4127) // conditional expression is constant
+#endif
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_tail_quantile_impl
+    //  Tail quantile estimation based on order statistics of weighted samples
+    /**
+        @brief Tail quantile estimation based on order statistics of weighted samples (for both left and right tails)
+
+        An estimator \f$\hat{q}\f$ of tail quantiles with level \f$\alpha\f$ based on order statistics
+        \f$X_{1:n} \leq X_{2:n} \leq\dots\leq X_{n:n}\f$ of weighted samples are given by \f$X_{\lambda:n}\f$ (left tail)
+        and \f$X_{\rho:n}\f$ (right tail), where
+
+            \f[
+                \lambda = \inf\left\{ l \left| \frac{1}{\bar{w}_n}\sum_{i=1}^{l} w_i \geq \alpha \right. \right\}
+            \f]
+
+        and
+
+            \f[
+                \rho = \sup\left\{ r \left| \frac{1}{\bar{w}_n}\sum_{i=r}^{n} w_i \geq (1 - \alpha) \right. \right\},
+            \f]
+
+        \f$n\f$ being the number of samples and \f$\bar{w}_n\f$ the sum of all weights.
+
+        @param quantile_probability
+    */
+    template<typename Sample, typename Weight, typename LeftRight>
+    struct weighted_tail_quantile_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Weight, std::size_t>::result_type float_type;
+        // for boost::result_of
+        typedef Sample result_type;
+
+        weighted_tail_quantile_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            float_type threshold = sum_of_weights(args)
+                             * ( ( is_same<LeftRight, left>::value ) ? args[quantile_probability] : 1. - args[quantile_probability] );
+
+            std::size_t n = 0;
+            Weight sum = Weight(0);
+
+            while (sum < threshold)
+            {
+                if (n < static_cast<std::size_t>(tail_weights(args).size()))
+                {
+                    sum += *(tail_weights(args).begin() + n);
+                    n++;
+                }
+                else
+                {
+                    if (std::numeric_limits<result_type>::has_quiet_NaN)
+                    {
+                        return std::numeric_limits<result_type>::quiet_NaN();
+                    }
+                    else
+                    {
+                        std::ostringstream msg;
+                        msg << "index n = " << n << " is not in valid range [0, " << tail(args).size() << ")";
+                        boost::throw_exception(std::runtime_error(msg.str()));
+                        return Sample(0);
+                    }
+                }
+            }
+
+            // Note that the cached samples of the left are sorted in ascending order,
+            // whereas the samples of the right tail are sorted in descending order
+            return *(boost::begin(tail(args)) + n - 1);
+        }
+    };
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_tail_quantile<>
+//
+namespace tag
+{
+    template<typename LeftRight>
+    struct weighted_tail_quantile
+      : depends_on<sum_of_weights, tail_weights<LeftRight> >
+    {
+        /// INTERNAL ONLY
+        typedef accumulators::impl::weighted_tail_quantile_impl<mpl::_1, mpl::_2, LeftRight> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_tail_quantile
+//
+namespace extract
+{
+    extractor<tag::quantile> const weighted_tail_quantile = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_tail_quantile)
+}
+
+using extract::weighted_tail_quantile;
+
+}} // namespace boost::accumulators
+
+#ifdef _MSC_VER
+# pragma warning(pop)
+#endif
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_tail_variate_means.hpp b/boost/accumulators/statistics/weighted_tail_variate_means.hpp
new file mode 100644
index 0000000..da18189
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_tail_variate_means.hpp
@@ -0,0 +1,242 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_tail_variate_means.hpp
+//
+//  Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_TAIL_VARIATE_MEANS_HPP_DE_01_01_2006
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_TAIL_VARIATE_MEANS_HPP_DE_01_01_2006
+
+#include <numeric>
+#include <vector>
+#include <limits>
+#include <functional>
+#include <sstream>
+#include <stdexcept>
+#include <boost/throw_exception.hpp>
+#include <boost/parameter/keyword.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/tail.hpp>
+#include <boost/accumulators/statistics/tail_variate.hpp>
+#include <boost/accumulators/statistics/tail_variate_means.hpp>
+#include <boost/accumulators/statistics/weighted_tail_mean.hpp>
+#include <boost/accumulators/statistics/parameters/quantile_probability.hpp>
+
+#ifdef _MSC_VER
+# pragma warning(push)
+# pragma warning(disable: 4127) // conditional expression is constant
+#endif
+
+namespace boost
+{
+    // for _BinaryOperatrion2 in std::inner_product below
+    // mutliplies two values and promotes the result to double
+    namespace numeric { namespace functional
+    {
+        ///////////////////////////////////////////////////////////////////////////////
+        // numeric::functional::multiply_and_promote_to_double
+        template<typename T, typename U>
+        struct multiply_and_promote_to_double
+          : multiplies<T, double const>
+        {
+        };
+    }}
+}
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    /**
+        @brief Estimation of the absolute and relative weighted tail variate means (for both left and right tails)
+
+        For all \f$j\f$-th variates associated to the
+
+        \f[
+            \lambda = \inf\left\{ l \left| \frac{1}{\bar{w}_n}\sum_{i=1}^{l} w_i \geq \alpha \right. \right\}
+        \f]
+
+        smallest samples (left tail) or the weighted mean of the
+
+        \f[
+            n + 1 - \rho = n + 1 - \sup\left\{ r \left| \frac{1}{\bar{w}_n}\sum_{i=r}^{n} w_i \geq (1 - \alpha) \right. \right\}
+        \f]
+
+        largest samples (right tail), the absolute weighted tail means \f$\widehat{ATM}_{n,\alpha}(X, j)\f$
+        are computed and returned as an iterator range. Alternatively, the relative weighted tail means
+        \f$\widehat{RTM}_{n,\alpha}(X, j)\f$ are returned, which are the absolute weighted tail means
+        normalized with the weighted (non-coherent) sample tail mean \f$\widehat{NCTM}_{n,\alpha}(X)\f$.
+
+        \f[
+            \widehat{ATM}_{n,\alpha}^{\mathrm{right}}(X, j) =
+                \frac{1}{\sum_{i=\rho}^n w_i}
+                \sum_{i=\rho}^n w_i \xi_{j,i}
+        \f]
+
+        \f[
+            \widehat{ATM}_{n,\alpha}^{\mathrm{left}}(X, j) =
+                \frac{1}{\sum_{i=1}^{\lambda}}
+                \sum_{i=1}^{\lambda} w_i \xi_{j,i}
+        \f]
+
+        \f[
+            \widehat{RTM}_{n,\alpha}^{\mathrm{right}}(X, j) =
+                \frac{\sum_{i=\rho}^n w_i \xi_{j,i}}
+            {\sum_{i=\rho}^n w_i \widehat{NCTM}_{n,\alpha}^{\mathrm{right}}(X)}
+        \f]
+
+        \f[
+            \widehat{RTM}_{n,\alpha}^{\mathrm{left}}(X, j) =
+                \frac{\sum_{i=1}^{\lambda} w_i \xi_{j,i}}
+            {\sum_{i=1}^{\lambda} w_i \widehat{NCTM}_{n,\alpha}^{\mathrm{left}}(X)}
+        \f]
+    */
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_tail_variate_means_impl
+    //  by default: absolute weighted_tail_variate_means
+    template<typename Sample, typename Weight, typename Impl, typename LeftRight, typename VariateType>
+    struct weighted_tail_variate_means_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::average<Weight, Weight>::result_type float_type;
+        typedef typename numeric::functional::average<typename numeric::functional::multiplies<VariateType, Weight>::result_type, Weight>::result_type array_type;
+        // for boost::result_of
+        typedef iterator_range<typename array_type::iterator> result_type;
+
+        weighted_tail_variate_means_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            float_type threshold = sum_of_weights(args)
+                             * ( ( is_same<LeftRight, left>::value ) ? args[quantile_probability] : 1. - args[quantile_probability] );
+
+            std::size_t n = 0;
+            Weight sum = Weight(0);
+
+            while (sum < threshold)
+            {
+                if (n < static_cast<std::size_t>(tail_weights(args).size()))
+                {
+                    sum += *(tail_weights(args).begin() + n);
+                    n++;
+                }
+                else
+                {
+                    if (std::numeric_limits<float_type>::has_quiet_NaN)
+                    {
+                        std::fill(
+                            this->tail_means_.begin()
+                          , this->tail_means_.end()
+                          , std::numeric_limits<float_type>::quiet_NaN()
+                        );
+                    }
+                    else
+                    {
+                        std::ostringstream msg;
+                        msg << "index n = " << n << " is not in valid range [0, " << tail(args).size() << ")";
+                        boost::throw_exception(std::runtime_error(msg.str()));
+                    }
+                }
+            }
+
+            std::size_t num_variates = tail_variate(args).begin()->size();
+
+            this->tail_means_.clear();
+            this->tail_means_.resize(num_variates, Sample(0));
+
+            this->tail_means_ = std::inner_product(
+                tail_variate(args).begin()
+              , tail_variate(args).begin() + n
+              , tail_weights(args).begin()
+              , this->tail_means_
+              , numeric::functional::plus<array_type const, array_type const>()
+              , numeric::functional::multiply_and_promote_to_double<VariateType const, Weight const>()
+            );
+
+            float_type factor = sum * ( (is_same<Impl, relative>::value) ? non_coherent_weighted_tail_mean(args) : 1. );
+
+            std::transform(
+                this->tail_means_.begin()
+              , this->tail_means_.end()
+              , this->tail_means_.begin()
+              , std::bind2nd(numeric::functional::divides<typename array_type::value_type const, float_type const>(), factor)
+            );
+
+            return make_iterator_range(this->tail_means_);
+        }
+
+    private:
+
+        mutable array_type tail_means_;
+
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::absolute_weighted_tail_variate_means
+// tag::relative_weighted_tail_variate_means
+//
+namespace tag
+{
+    template<typename LeftRight, typename VariateType, typename VariateTag>
+    struct absolute_weighted_tail_variate_means
+      : depends_on<non_coherent_weighted_tail_mean<LeftRight>, tail_variate<VariateType, VariateTag, LeftRight>, tail_weights<LeftRight> >
+    {
+        typedef accumulators::impl::weighted_tail_variate_means_impl<mpl::_1, mpl::_2, absolute, LeftRight, VariateType> impl;
+    };
+    template<typename LeftRight, typename VariateType, typename VariateTag>
+    struct relative_weighted_tail_variate_means
+      : depends_on<non_coherent_weighted_tail_mean<LeftRight>, tail_variate<VariateType, VariateTag, LeftRight>, tail_weights<LeftRight> >
+    {
+        typedef accumulators::impl::weighted_tail_variate_means_impl<mpl::_1, mpl::_2, relative, LeftRight, VariateType> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_tail_variate_means
+// extract::relative_weighted_tail_variate_means
+//
+namespace extract
+{
+    extractor<tag::abstract_absolute_tail_variate_means> const weighted_tail_variate_means = {};
+    extractor<tag::abstract_relative_tail_variate_means> const relative_weighted_tail_variate_means = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_tail_variate_means)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(relative_weighted_tail_variate_means)
+}
+
+using extract::weighted_tail_variate_means;
+using extract::relative_weighted_tail_variate_means;
+
+// weighted_tail_variate_means<LeftRight, VariateType, VariateTag>(absolute) -> absolute_weighted_tail_variate_means<LeftRight, VariateType, VariateTag>
+template<typename LeftRight, typename VariateType, typename VariateTag>
+struct as_feature<tag::weighted_tail_variate_means<LeftRight, VariateType, VariateTag>(absolute)>
+{
+    typedef tag::absolute_weighted_tail_variate_means<LeftRight, VariateType, VariateTag> type;
+};
+
+// weighted_tail_variate_means<LeftRight, VariateType, VariateTag>(relative) -> relative_weighted_tail_variate_means<LeftRight, VariateType, VariateTag>
+template<typename LeftRight, typename VariateType, typename VariateTag>
+struct as_feature<tag::weighted_tail_variate_means<LeftRight, VariateType, VariateTag>(relative)>
+{
+    typedef tag::relative_weighted_tail_variate_means<LeftRight, VariateType, VariateTag> type;
+};
+
+}} // namespace boost::accumulators
+
+#ifdef _MSC_VER
+# pragma warning(pop)
+#endif
+
+#endif
diff --git a/boost/accumulators/statistics/weighted_variance.hpp b/boost/accumulators/statistics/weighted_variance.hpp
new file mode 100644
index 0000000..e91fdc1
--- /dev/null
+++ b/boost/accumulators/statistics/weighted_variance.hpp
@@ -0,0 +1,186 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_variance.hpp
+//
+//  Copyright 2005 Daniel Egloff, Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_VARIANCE_HPP_EAN_28_10_2005
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_VARIANCE_HPP_EAN_28_10_2005
+
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+#include <boost/accumulators/numeric/functional.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/count.hpp>
+#include <boost/accumulators/statistics/variance.hpp>
+#include <boost/accumulators/statistics/weighted_sum.hpp>
+#include <boost/accumulators/statistics/weighted_mean.hpp>
+#include <boost/accumulators/statistics/weighted_moment.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+    //! Lazy calculation of variance of weighted samples.
+    /*!
+        The default implementation of the variance of weighted samples is based on the second moment
+        \f$\widehat{m}_n^{(2)}\f$ (weighted_moment<2>) and the mean\f$ \hat{\mu}_n\f$ (weighted_mean):
+        \f[
+            \hat{\sigma}_n^2 = \widehat{m}_n^{(2)}-\hat{\mu}_n^2,
+        \f]
+        where \f$n\f$ is the number of samples.
+    */
+    template<typename Sample, typename Weight, typename MeanFeature>
+    struct lazy_weighted_variance_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample;
+        // for boost::result_of
+        typedef typename numeric::functional::average<weighted_sample, Weight>::result_type result_type;
+
+        lazy_weighted_variance_impl(dont_care) {}
+
+        template<typename Args>
+        result_type result(Args const &args) const
+        {
+            extractor<MeanFeature> const some_mean = {};
+            result_type tmp = some_mean(args);
+            return accumulators::weighted_moment<2>(args) - tmp * tmp;
+        }
+    };
+
+    //! Iterative calculation of variance of weighted samples.
+    /*!
+        Iterative calculation of variance of weighted samples:
+        \f[
+            \hat{\sigma}_n^2 =
+                \frac{\bar{w}_n - w_n}{\bar{w}_n}\hat{\sigma}_{n - 1}^2
+              + \frac{w_n}{\bar{w}_n - w_n}\left(X_n - \hat{\mu}_n\right)^2
+            ,\quad n\ge2,\quad\hat{\sigma}_0^2 = 0.
+        \f]
+        where \f$\bar{w}_n\f$ is the sum of the \f$n\f$ weights \f$w_i\f$ and \f$\hat{\mu}_n\f$
+        the estimate of the mean of the weighted smaples. Note that the sample variance is not defined for
+        \f$n <= 1\f$.
+    */
+    template<typename Sample, typename Weight, typename MeanFeature, typename Tag>
+    struct weighted_variance_impl
+      : accumulator_base
+    {
+        typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample;
+        // for boost::result_of
+        typedef typename numeric::functional::average<weighted_sample, Weight>::result_type result_type;
+
+        template<typename Args>
+        weighted_variance_impl(Args const &args)
+          : weighted_variance(numeric::average(args[sample | Sample()], numeric::one<Weight>::value))
+        {
+        }
+
+        template<typename Args>
+        void operator ()(Args const &args)
+        {
+            std::size_t cnt = count(args);
+
+            if(cnt > 1)
+            {
+                extractor<MeanFeature> const some_mean = {};
+
+                result_type tmp = args[parameter::keyword<Tag>::get()] - some_mean(args);
+
+                this->weighted_variance =
+                    numeric::average(this->weighted_variance * (sum_of_weights(args) - args[weight]), sum_of_weights(args))
+                  + numeric::average(tmp * tmp * args[weight], sum_of_weights(args) - args[weight] );
+            }
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->weighted_variance;
+        }
+
+    private:
+        result_type weighted_variance;
+    };
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_variance
+// tag::immediate_weighted_variance
+//
+namespace tag
+{
+    struct lazy_weighted_variance
+      : depends_on<weighted_moment<2>, weighted_mean>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::lazy_weighted_variance_impl<mpl::_1, mpl::_2, weighted_mean> impl;
+    };
+
+    struct weighted_variance
+      : depends_on<count, immediate_weighted_mean>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::weighted_variance_impl<mpl::_1, mpl::_2, immediate_weighted_mean, sample> impl;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_variance
+// extract::immediate_weighted_variance
+//
+namespace extract
+{
+    extractor<tag::lazy_weighted_variance> const lazy_weighted_variance = {};
+    extractor<tag::weighted_variance> const weighted_variance = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(lazy_weighted_variance)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_variance)
+}
+
+using extract::lazy_weighted_variance;
+using extract::weighted_variance;
+
+// weighted_variance(lazy) -> lazy_weighted_variance
+template<>
+struct as_feature<tag::weighted_variance(lazy)>
+{
+    typedef tag::lazy_weighted_variance type;
+};
+
+// weighted_variance(immediate) -> weighted_variance
+template<>
+struct as_feature<tag::weighted_variance(immediate)>
+{
+    typedef tag::weighted_variance type;
+};
+
+////////////////////////////////////////////////////////////////////////////
+//// droppable_accumulator<weighted_variance_impl>
+////  need to specialize droppable lazy weighted_variance to cache the result at the
+////  point the accumulator is dropped.
+///// INTERNAL ONLY
+/////
+//template<typename Sample, typename Weight, typename MeanFeature>
+//struct droppable_accumulator<impl::weighted_variance_impl<Sample, Weight, MeanFeature> >
+//  : droppable_accumulator_base<
+//        with_cached_result<impl::weighted_variance_impl<Sample, Weight, MeanFeature> >
+//    >
+//{
+//    template<typename Args>
+//    droppable_accumulator(Args const &args)
+//      : droppable_accumulator::base(args)
+//    {
+//    }
+//};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics/with_error.hpp b/boost/accumulators/statistics/with_error.hpp
new file mode 100644
index 0000000..adafc8e
--- /dev/null
+++ b/boost/accumulators/statistics/with_error.hpp
@@ -0,0 +1,44 @@
+///////////////////////////////////////////////////////////////////////////////
+// with_error.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_WITH_ERROR_HPP_EAN_01_11_2005
+#define BOOST_ACCUMULATORS_STATISTICS_WITH_ERROR_HPP_EAN_01_11_2005
+
+#include <boost/preprocessor/repetition/enum_params.hpp>
+#include <boost/mpl/vector.hpp>
+#include <boost/mpl/transform_view.hpp>
+#include <boost/mpl/placeholders.hpp>
+#include <boost/accumulators/statistics_fwd.hpp>
+#include <boost/accumulators/statistics/error_of.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace detail
+{
+    template<typename Feature>
+    struct error_of_tag
+    {
+        typedef tag::error_of<Feature> type;
+    };
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// with_error
+//
+template<BOOST_PP_ENUM_PARAMS(BOOST_ACCUMULATORS_MAX_FEATURES, typename Feature)>
+struct with_error
+  : mpl::transform_view<
+        mpl::vector<BOOST_PP_ENUM_PARAMS(BOOST_ACCUMULATORS_MAX_FEATURES, Feature)>
+      , detail::error_of_tag<mpl::_1>
+    >
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif
diff --git a/boost/accumulators/statistics_fwd.hpp b/boost/accumulators/statistics_fwd.hpp
new file mode 100644
index 0000000..61904f3
--- /dev/null
+++ b/boost/accumulators/statistics_fwd.hpp
@@ -0,0 +1,432 @@
+///////////////////////////////////////////////////////////////////////////////
+// statistics_fwd.hpp
+//
+//  Copyright 2005 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_ACCUMULATORS_STATISTICS_STATISTICS_FWD_HPP_EAN_23_11_2005
+#define BOOST_ACCUMULATORS_STATISTICS_STATISTICS_FWD_HPP_EAN_23_11_2005
+
+#include <boost/mpl/apply_fwd.hpp> // for mpl::na
+#include <boost/mpl/print.hpp>
+#include <boost/preprocessor/repetition/enum_params_with_a_default.hpp>
+#include <boost/accumulators/accumulators_fwd.hpp>
+#include <boost/accumulators/framework/depends_on.hpp>
+#include <boost/accumulators/framework/extractor.hpp>
+
+namespace boost { namespace accumulators
+{
+
+///////////////////////////////////////////////////////////////////////////////
+// base struct and base extractor for quantiles
+namespace tag
+{
+    struct quantile
+      : depends_on<>
+    {
+        typedef mpl::print<class ____MISSING_SPECIFIC_QUANTILE_FEATURE_IN_ACCUMULATOR_SET____ > impl;
+    };
+}
+namespace extract
+{
+    extractor<tag::quantile> const quantile = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(quantile)
+}
+using extract::quantile;
+
+///////////////////////////////////////////////////////////////////////////////
+// base struct and base extractor for *coherent* tail means
+namespace tag
+{
+    struct tail_mean
+      : depends_on<>
+    {
+        typedef mpl::print<class ____MISSING_SPECIFIC_TAIL_MEAN_FEATURE_IN_ACCUMULATOR_SET____ > impl;
+    };
+}
+namespace extract
+{
+    extractor<tag::tail_mean> const tail_mean = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(tail_mean)
+}
+using extract::tail_mean;
+
+namespace tag
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // Variates tags
+    struct weights;
+    struct covariate1;
+    struct covariate2;
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // Statistic tags
+    struct count;
+    template<typename VariateType, typename VariateTag>
+    struct covariance;
+    struct density;
+    template<typename Feature>
+    struct error_of;
+    struct extended_p_square;
+    struct extended_p_square_quantile;
+    struct extended_p_square_quantile_quadratic;
+    struct kurtosis;
+    struct max;
+    struct mean;
+    struct immediate_mean;
+    struct mean_of_weights;
+    struct immediate_mean_of_weights;
+    template<typename VariateType, typename VariateTag>
+    struct mean_of_variates;
+    template<typename VariateType, typename VariateTag>
+    struct immediate_mean_of_variates;
+    struct median;
+    struct with_density_median;
+    struct with_p_square_cumulative_distribution_median;
+    struct min;
+    template<int N>
+    struct moment;
+    template<typename LeftRight>
+    struct peaks_over_threshold;
+    template<typename LeftRight>
+    struct peaks_over_threshold_prob;
+    template<typename LeftRight>
+    struct pot_tail_mean;
+    template<typename LeftRight>
+    struct pot_tail_mean_prob;
+    template<typename LeftRight>
+    struct pot_quantile;
+    template<typename LeftRight>
+    struct pot_quantile_prob;
+    struct p_square_cumulative_distribution;
+    struct p_square_quantile;
+    struct p_square_quantile_for_median;
+    struct skewness;
+    struct sum;
+    struct sum_of_weights;
+    template<typename VariateType, typename VariateTag>
+    struct sum_of_variates;
+    struct sum_kahan;
+    struct sum_of_weights_kahan;
+    template<typename VariateType, typename VariateTag>
+    struct sum_of_variates_kahan;
+    template<typename LeftRight>
+    struct tail;
+    template<typename LeftRight>
+    struct coherent_tail_mean;
+    template<typename LeftRight>
+    struct non_coherent_tail_mean;
+    template<typename LeftRight>
+    struct tail_quantile;
+    template<typename VariateType, typename VariateTag, typename LeftRight>
+    struct tail_variate;
+    template<typename LeftRight>
+    struct tail_weights;
+    template<typename VariateType, typename VariateTag, typename LeftRight>
+    struct right_tail_variate;
+    template<typename VariateType, typename VariateTag, typename LeftRight>
+    struct left_tail_variate;
+    template<typename LeftRight, typename VariateType, typename VariateTag>
+    struct tail_variate_means;
+    template<typename LeftRight, typename VariateType, typename VariateTag>
+    struct absolute_tail_variate_means;
+    template<typename LeftRight, typename VariateType, typename VariateTag>
+    struct relative_tail_variate_means;
+    struct lazy_variance;
+    struct variance;
+    template<typename VariateType, typename VariateTag>
+    struct weighted_covariance;
+    struct weighted_density;
+    struct weighted_kurtosis;
+    struct weighted_mean;
+    struct immediate_weighted_mean;
+    template<typename VariateType, typename VariateTag>
+    struct weighted_mean_of_variates;
+    template<typename VariateType, typename VariateTag>
+    struct immediate_weighted_mean_of_variates;
+    struct weighted_median;
+    struct with_density_weighted_median;
+    struct with_p_square_cumulative_distribution_weighted_median;
+    struct weighted_extended_p_square;
+    struct weighted_extended_p_square_quantile;
+    struct weighted_extended_p_square_quantile_quadratic;
+    template<int N>
+    struct weighted_moment;
+    template<typename LeftRight>
+    struct weighted_peaks_over_threshold;
+    template<typename LeftRight>
+    struct weighted_peaks_over_threshold_prob;
+    template<typename LeftRight>
+    struct weighted_pot_quantile;
+    template<typename LeftRight>
+    struct weighted_pot_quantile_prob;
+    template<typename LeftRight>
+    struct weighted_pot_tail_mean;
+    template<typename LeftRight>
+    struct weighted_pot_tail_mean_prob;
+    struct weighted_p_square_cumulative_distribution;
+    struct weighted_p_square_quantile;
+    struct weighted_p_square_quantile_for_median;
+    struct weighted_skewness;
+    template<typename LeftRight>
+    struct weighted_tail_quantile;
+    template<typename LeftRight>
+    struct non_coherent_weighted_tail_mean;
+    template<typename LeftRight>
+    struct weighted_tail_quantile;
+    template<typename LeftRight, typename VariateType, typename VariateTag>
+    struct weighted_tail_variate_means;
+    template<typename LeftRight, typename VariateType, typename VariateTag>
+    struct absolute_weighted_tail_variate_means;
+    template<typename LeftRight, typename VariateType, typename VariateTag>
+    struct relative_weighted_tail_variate_means;
+    struct lazy_weighted_variance;
+    struct weighted_variance;
+    struct weighted_sum;
+    template<typename VariateType, typename VariateTag>
+    struct weighted_sum_of_variates;
+    struct rolling_window_plus1;
+    struct rolling_window;
+    struct rolling_sum;
+    struct rolling_count;
+    struct rolling_mean;
+} // namespace tag
+
+namespace impl
+{
+    ///////////////////////////////////////////////////////////////////////////////
+    // Statistics impls
+    struct count_impl;
+
+    template<typename Sample, typename VariateType, typename VariateTag>
+    struct covariance_impl;
+
+    template<typename Sample>
+    struct density_impl;
+
+    template<typename Sample, typename Feature>
+    struct error_of_impl;
+
+    template<typename Sample, typename Variance>
+    struct error_of_mean_impl;
+
+    template<typename Sample>
+    struct extended_p_square_impl;
+
+    template<typename Sample, typename Impl1, typename Impl2>
+    struct extended_p_square_quantile_impl;
+
+    template<typename Sample>
+    struct kurtosis_impl;
+
+    template<typename Sample>
+    struct max_impl;
+
+    template<typename Sample>
+    struct median_impl;
+
+    template<typename Sample>
+    struct with_density_median_impl;
+
+    template<typename Sample>
+    struct with_p_square_cumulative_distribution_median_impl;
+
+    template<typename Sample>
+    struct min_impl;
+
+    template<typename Sample, typename SumFeature = tag::sum>
+    struct mean_impl;
+
+    template<typename Sample, typename Tag = tag::sample>
+    struct immediate_mean_impl;
+
+    template<typename N, typename Sample>
+    struct moment_impl;
+
+    template<typename Sample, typename LeftRight>
+    struct peaks_over_threshold_prob_impl;
+
+    template<typename Sample, typename Impl, typename LeftRight>
+    struct pot_quantile_impl;
+
+    template<typename Sample, typename Impl, typename LeftRight>
+    struct pot_tail_mean_impl;
+
+    template<typename Sample>
+    struct p_square_cumulative_distribution_impl;
+
+    template<typename Sample, typename Impl>
+    struct p_square_quantile_impl;
+
+    template<typename Sample>
+    struct skewness_impl;
+
+    template<typename Sample, typename Tag = tag::sample>
+    struct sum_impl;
+
+    template<typename Sample, typename Tag>
+    struct sum_kahan_impl;
+
+    template<typename Sample, typename LeftRight>
+    struct tail_impl;
+
+    template<typename Sample, typename LeftRight>
+    struct coherent_tail_mean_impl;
+
+    template<typename Sample, typename LeftRight>
+    struct non_coherent_tail_mean_impl;
+
+    template<typename Sample, typename LeftRight>
+    struct tail_quantile_impl;
+
+    template<typename VariateType, typename VariateTag, typename LeftRight>
+    struct tail_variate_impl;
+
+    template<typename Sample, typename Impl, typename LeftRight, typename VariateTag>
+    struct tail_variate_means_impl;
+
+    template<typename Sample, typename MeanFeature>
+    struct lazy_variance_impl;
+
+    template<typename Sample, typename MeanFeature, typename Tag>
+    struct variance_impl;
+
+    template<typename Sample, typename Weight, typename VariateType, typename VariateTag>
+    struct weighted_covariance_impl;
+
+    template<typename Sample, typename Weight>
+    struct weighted_density_impl;
+
+    template<typename Sample, typename Weight>
+    struct weighted_kurtosis_impl;
+
+    template<typename Sample>
+    struct weighted_median_impl;
+
+    template<typename Sample>
+    struct with_density_weighted_median_impl;
+
+    template<typename Sample, typename Weight>
+    struct with_p_square_cumulative_distribution_weighted_median_impl;
+
+    template<typename Sample, typename Weight, typename Tag>
+    struct weighted_mean_impl;
+
+    template<typename Sample, typename Weight, typename Tag>
+    struct immediate_weighted_mean_impl;
+
+    template<typename Sample, typename Weight, typename LeftRight>
+    struct weighted_peaks_over_threshold_impl;
+
+    template<typename Sample, typename Weight, typename LeftRight>
+    struct weighted_peaks_over_threshold_prob_impl;
+
+    template<typename Sample, typename Weight>
+    struct with_p_square_cumulative_distribution_weighted_median_impl;
+
+    template<typename Sample, typename Weight>
+    struct weighted_extended_p_square_impl;
+
+    template<typename N, typename Sample, typename Weight>
+    struct weighted_moment_impl;
+
+    template<typename Sample, typename Weight>
+    struct weighted_p_square_cumulative_distribution_impl;
+
+    template<typename Sample, typename Weight, typename Impl>
+    struct weighted_p_square_quantile_impl;
+
+    template<typename Sample, typename Weight>
+    struct weighted_skewness_impl;
+
+    template<typename Sample, typename Weight, typename Tag>
+    struct weighted_sum_impl;
+
+    template<typename Sample, typename Weight, typename Tag>
+    struct weighted_sum_kahan_impl;
+
+    template<typename Sample, typename Weight, typename LeftRight>
+    struct non_coherent_weighted_tail_mean_impl;
+
+    template<typename Sample, typename Weight, typename LeftRight>
+    struct weighted_tail_quantile_impl;
+
+    template<typename Sample, typename Weight, typename Impl, typename LeftRight, typename VariateType>
+    struct weighted_tail_variate_means_impl;
+
+    template<typename Sample, typename Weight, typename MeanFeature>
+    struct lazy_weighted_variance_impl;