third_party/boost/optional/doc/91_relnotes.qbk - platform/external/sdv/vsomeip - Git at Google

 [/
     Boost.Optional

     Copyright (c) 2015 - 2018 Andrzej Krzemienski

     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)
 ]


 [section:relnotes Release Notes]

 [heading Boost Release 1.76]

 * Fixed MSVC warning C4702.

 [heading Boost Release 1.75]

 * `boost::none` is `constexpr`-declared.

 * Fixed [@https://github.com/boostorg/optional/issues/78 issue #78].

 [heading Boost Release 1.73]

 * Fixed [@https://github.com/boostorg/optional/issues/78 issue #78].
 * `boost::none` is now declared as an inline variable (on compilers that support it): there is only one instance of `boost::none` across all translation units.
 * Fixed a number of compilation errors in GCC 4.4.7 in `optional<T>` for trivial `T`s. Thanks to Robert Leahy for the fix. For details see [@https://github.com/boostorg/optional/pull/80 pr #78].
 * Now surpressing warning `-Wweak-vtables`.

 [heading Boost Release 1.69]

 * Remove deprecation mark from `reset()` method (without arguments).
 * Fixed [@https://github.com/boostorg/optional/issues/59 issue #59].
 * Fixed bug with initialization of certain wrapper types in clang with -std=c++03. See [@https://github.com/boostorg/optional/pull/64 pr #64].

 [heading Boost Release 1.68]

 * Added member function `has_value()` for compatibility with `std::optional` ([@https://github.com/boostorg/optional/issues/52 issue #52]).
 * Added member function `map()` for transforming `optional<T>` into `optional<U>` using a function of type `T -> U`.
 * Added member function `flat_map()` for transforming `optional<T>` into `optional<U>` using a function of type `T -> optonal<U>`.


 [heading Boost Release 1.67]

 * Fixed [@https://github.com/boostorg/optional/issues/46 issue #46].
 * Fixed `-Wzero-as-null-pointer-constant` warnings.


 [heading Boost Release 1.66]

 * On newer compilers `optional` is now trivially-copyable for scalar `T`s. This uses a different storage (just `T` rather than `aligned_storage`). We require the compiler to support defaulted functions.
 * Changed the implementation of `operator==` to get rid of the `-Wmaybe-uninitialized` false-positive warning from GCC.

 [heading Boost Release 1.63]
 * Added two new in-place constructors. They work similarly to `emplace()` functions: they initialize the contained value by perfect-forwarding the obtained arguments. One constructor always initializes the contained value, the other based on a boolean condition.
 * Syntax `o = {}` now correctly un-initializes optional, just like in `std::optional`.
 * Fixed [@https://svn.boost.org/trac/boost/ticket/12203 Trac #12203].
 * Fixed [@https://svn.boost.org/trac/boost/ticket/12563 Trac #12563].


 [heading Boost Release 1.62]

 * Fixed [@https://svn.boost.org/trac/boost/ticket/12179 Trac #12179].


 [heading Boost Release 1.61]

 * Now `boost::optional` is specialized for reference parameters. This addresses a couple of issues:
   * the `sizeof` of optional reference is that of a pointer,
   * some bugs connected to copying optional references are gone,
   * all run-time bugs caused by incorrect reference binding on some compilers are now turned into compile-time errors,
   * you can swap optional references: it is like swapping pointers: shalow, underlying objects are not affected,
   * optional references to abstract types work.
 * Documented nested typedefs ([@https://svn.boost.org/trac/boost/ticket/5193 Trac #5193]).
 * Made the perfect-forwarding constructor SFINAE-friendly, which fixes [@https://svn.boost.org/trac/boost/ticket/12002 Trac #12002]. However, this only works in the newer platforms that correctly implement C++11 `<type_traits>`.
 * Fixed [@https://svn.boost.org/trac/boost/ticket/10445 Trac #10445].


 [heading Boost Release 1.60]

 * Changed the implementation of `boost::none` again. Now it is a const object with internal linkage (as any other tag). This fixes [@https://svn.boost.org/trac/boost/ticket/11203 Trac #11203].


 [heading Boost Release 1.59]

 * For C++03 compilers, added 0-argument overload for member function `emplace()`, and therewith removed the dependency on `<boost/utility/in_place_factory.hpp>`.
 * Fixed [@https://svn.boost.org/trac/boost/ticket/11241 Trac #11241].

 [heading Boost Release 1.58]

 * `boost::none_t` is no longer convertible from literal `0`. This avoids a bug where `optional<rational<int>> oi = 0;` would initialize an optional object with no contained value.
 * Improved the trick that prevents streaming out `optional` without header `optional_io.hpp` by using safe-bool idiom. This addresses [@https://svn.boost.org/trac/boost/ticket/10825 Trac #10825].
 * IOStream operators are now mentioned in documentation.
 * Added a way to manually disable move semantics: just define macro `BOOST_OPTIONAL_CONFIG_NO_RVALUE_REFERENCES`. This can be used to work around [@https://svn.boost.org/trac/boost/ticket/10399 Trac #10399].
 * It is no longer possible to assign `optional<U>` to `optional<T>` when `U` is not assignable or convertible to `T` ([@https://svn.boost.org/trac/boost/ticket/11087 Trac #11087]).
 * Value accessors now work correctly on rvalues of `optional<T&>` ([@https://svn.boost.org/trac/boost/ticket/10839 Trac #10839]).


 [heading Boost Release 1.57]

 * [@https://github.com/boostorg/optional/pull/9 Git pull #9]: ['"Supply `<string>` to fix C++03 compile error on `logic_error("...")`"].


 [heading Boost Release 1.56]

 * Added support for rvalue references. Now `optional<T>` works with moveable but non-copyable `T`'s,
 * Improved `swap` (now uses move operations),
 * Added function `emplace()`. This is the last of the requests from [@https://svn.boost.org/trac/boost/ticket/1841 Trac #1841],
 * `optional` is moveable, including conditional `noexcept` specifications, which make it `move_if_noexcept`-friendly,
 * Using explicit operator bool() on platforms that support it ([@https://svn.boost.org/trac/boost/ticket/4227 Trac #4227]) (breaking change),
 * Forward declaration of `operator<<(ostream&, optional const&)` to prevent inadvertent incorrect serialization of optional objects,
 * Removed deprecated function `reset()` from examples ([@https://svn.boost.org/trac/boost/ticket/9005 Trac #9005]),
 * Equality comparison with `boost::none` does not require that `T` be EqualityComparable,
 * Optional rvalue references are explicitly disallowed,
 * Binding temporaries to optional references is explicitly disallowed (breaking change),
 * More ways to access the contained value, functions `value()`, `value_or()`, `value_or_eval()`,
 * Updated and reorganized documentation, added tutorial and quick guide sections.


 [endsect][/ relnotes]
	[/
	Boost.Optional

	Copyright (c) 2015 - 2018 Andrzej Krzemienski

	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)
	]


	[section:relnotes Release Notes]

	[heading Boost Release 1.76]

	* Fixed MSVC warning C4702.

	[heading Boost Release 1.75]

	* `boost::none` is `constexpr`-declared.

	* Fixed [@https://github.com/boostorg/optional/issues/78 issue #78].

	[heading Boost Release 1.73]

	* Fixed [@https://github.com/boostorg/optional/issues/78 issue #78].
	* `boost::none` is now declared as an inline variable (on compilers that support it): there is only one instance of `boost::none` across all translation units.
	* Fixed a number of compilation errors in GCC 4.4.7 in `optional<T>` for trivial `T`s. Thanks to Robert Leahy for the fix. For details see [@https://github.com/boostorg/optional/pull/80 pr #78].
	* Now surpressing warning `-Wweak-vtables`.

	[heading Boost Release 1.69]

	* Remove deprecation mark from `reset()` method (without arguments).
	* Fixed [@https://github.com/boostorg/optional/issues/59 issue #59].
	* Fixed bug with initialization of certain wrapper types in clang with -std=c++03. See [@https://github.com/boostorg/optional/pull/64 pr #64].

	[heading Boost Release 1.68]

	* Added member function `has_value()` for compatibility with `std::optional` ([@https://github.com/boostorg/optional/issues/52 issue #52]).
	* Added member function `map()` for transforming `optional<T>` into `optional<U>` using a function of type `T -> U`.
	* Added member function `flat_map()` for transforming `optional<T>` into `optional<U>` using a function of type `T -> optonal<U>`.


	[heading Boost Release 1.67]

	* Fixed [@https://github.com/boostorg/optional/issues/46 issue #46].
	* Fixed `-Wzero-as-null-pointer-constant` warnings.


	[heading Boost Release 1.66]

	* On newer compilers `optional` is now trivially-copyable for scalar `T`s. This uses a different storage (just `T` rather than `aligned_storage`). We require the compiler to support defaulted functions.
	* Changed the implementation of `operator==` to get rid of the `-Wmaybe-uninitialized` false-positive warning from GCC.

	[heading Boost Release 1.63]
	* Added two new in-place constructors. They work similarly to `emplace()` functions: they initialize the contained value by perfect-forwarding the obtained arguments. One constructor always initializes the contained value, the other based on a boolean condition.
	* Syntax `o = {}` now correctly un-initializes optional, just like in `std::optional`.
	* Fixed [@https://svn.boost.org/trac/boost/ticket/12203 Trac #12203].
	* Fixed [@https://svn.boost.org/trac/boost/ticket/12563 Trac #12563].


	[heading Boost Release 1.62]

	* Fixed [@https://svn.boost.org/trac/boost/ticket/12179 Trac #12179].


	[heading Boost Release 1.61]

	* Now `boost::optional` is specialized for reference parameters. This addresses a couple of issues:
	* the `sizeof` of optional reference is that of a pointer,
	* some bugs connected to copying optional references are gone,
	* all run-time bugs caused by incorrect reference binding on some compilers are now turned into compile-time errors,
	* you can swap optional references: it is like swapping pointers: shalow, underlying objects are not affected,
	* optional references to abstract types work.
	* Documented nested typedefs ([@https://svn.boost.org/trac/boost/ticket/5193 Trac #5193]).
	* Made the perfect-forwarding constructor SFINAE-friendly, which fixes [@https://svn.boost.org/trac/boost/ticket/12002 Trac #12002]. However, this only works in the newer platforms that correctly implement C++11 `<type_traits>`.
	* Fixed [@https://svn.boost.org/trac/boost/ticket/10445 Trac #10445].


	[heading Boost Release 1.60]

	* Changed the implementation of `boost::none` again. Now it is a const object with internal linkage (as any other tag). This fixes [@https://svn.boost.org/trac/boost/ticket/11203 Trac #11203].


	[heading Boost Release 1.59]

	* For C++03 compilers, added 0-argument overload for member function `emplace()`, and therewith removed the dependency on `<boost/utility/in_place_factory.hpp>`.
	* Fixed [@https://svn.boost.org/trac/boost/ticket/11241 Trac #11241].

	[heading Boost Release 1.58]

	* `boost::none_t` is no longer convertible from literal `0`. This avoids a bug where `optional<rational<int>> oi = 0;` would initialize an optional object with no contained value.
	* Improved the trick that prevents streaming out `optional` without header `optional_io.hpp` by using safe-bool idiom. This addresses [@https://svn.boost.org/trac/boost/ticket/10825 Trac #10825].
	* IOStream operators are now mentioned in documentation.
	* Added a way to manually disable move semantics: just define macro `BOOST_OPTIONAL_CONFIG_NO_RVALUE_REFERENCES`. This can be used to work around [@https://svn.boost.org/trac/boost/ticket/10399 Trac #10399].
	* It is no longer possible to assign `optional<U>` to `optional<T>` when `U` is not assignable or convertible to `T` ([@https://svn.boost.org/trac/boost/ticket/11087 Trac #11087]).
	* Value accessors now work correctly on rvalues of `optional<T&>` ([@https://svn.boost.org/trac/boost/ticket/10839 Trac #10839]).


	[heading Boost Release 1.57]

	* [@https://github.com/boostorg/optional/pull/9 Git pull #9]: ['"Supply `<string>` to fix C++03 compile error on `logic_error("...")`"].


	[heading Boost Release 1.56]

	* Added support for rvalue references. Now `optional<T>` works with moveable but non-copyable `T`'s,
	* Improved `swap` (now uses move operations),
	* Added function `emplace()`. This is the last of the requests from [@https://svn.boost.org/trac/boost/ticket/1841 Trac #1841],
	* `optional` is moveable, including conditional `noexcept` specifications, which make it `move_if_noexcept`-friendly,
	* Using explicit operator bool() on platforms that support it ([@https://svn.boost.org/trac/boost/ticket/4227 Trac #4227]) (breaking change),
	* Forward declaration of `operator<<(ostream&, optional const&)` to prevent inadvertent incorrect serialization of optional objects,
	* Removed deprecated function `reset()` from examples ([@https://svn.boost.org/trac/boost/ticket/9005 Trac #9005]),
	* Equality comparison with `boost::none` does not require that `T` be EqualityComparable,
	* Optional rvalue references are explicitly disallowed,
	* Binding temporaries to optional references is explicitly disallowed (breaking change),
	* More ways to access the contained value, functions `value()`, `value_or()`, `value_or_eval()`,
	* Updated and reorganized documentation, added tutorial and quick guide sections.



	[endsect][/ relnotes]