| // Copyright (C) 2003, 2008 Fernando Luis Cacciola Carballal. |
| // Copyright (C) 2014-2016 Andrzej Krzemienski. |
| // |
| // Use, modification, and distribution is 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) |
| // |
| // See http://www.boost.org/libs/optional for documentation. |
| // |
| // You are welcome to contact the maintainer at: |
| // akrzemi1@gmail.com |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_OLD_OPTIONAL_IMPLEMENTATION_AJK_28JAN2015_HPP |
| #define BOOST_OPTIONAL_DETAIL_OLD_OPTIONAL_IMPLEMENTATION_AJK_28JAN2015_HPP |
| |
| #include <boost/detail/reference_content.hpp> |
| #include <boost/type_traits/is_reference.hpp> |
| #include <boost/type_traits/integral_constant.hpp> |
| #include <boost/type_traits/conditional.hpp> |
| |
| namespace boost { |
| |
| namespace optional_detail { |
| |
| |
| template<class T> |
| struct types_when_isnt_ref |
| { |
| typedef T const& reference_const_type ; |
| typedef T & reference_type ; |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| typedef T && rval_reference_type ; |
| typedef T && reference_type_of_temporary_wrapper; |
| #ifdef BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES |
| // GCC 4.4 has support for an early draft of rvalue references. The conforming version below |
| // causes warnings about returning references to a temporary. |
| static T&& move(T&& r) { return r; } |
| #else |
| static rval_reference_type move(reference_type r) { return boost::move(r); } |
| #endif |
| #endif |
| typedef T const* pointer_const_type ; |
| typedef T * pointer_type ; |
| typedef T const& argument_type ; |
| } ; |
| |
| template<class T> |
| struct types_when_is_ref |
| { |
| typedef BOOST_DEDUCED_TYPENAME remove_reference<T>::type raw_type ; |
| |
| typedef raw_type& reference_const_type ; |
| typedef raw_type& reference_type ; |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| typedef BOOST_DEDUCED_TYPENAME remove_const<raw_type>::type&& rval_reference_type ; |
| typedef raw_type& reference_type_of_temporary_wrapper; |
| static reference_type move(reference_type r) { return r; } |
| #endif |
| typedef raw_type* pointer_const_type ; |
| typedef raw_type* pointer_type ; |
| typedef raw_type& argument_type ; |
| } ; |
| |
| template <class To, class From> |
| void prevent_binding_rvalue_ref_to_optional_lvalue_ref() |
| { |
| #ifndef BOOST_OPTIONAL_CONFIG_ALLOW_BINDING_TO_RVALUES |
| BOOST_STATIC_ASSERT_MSG( |
| !boost::is_lvalue_reference<To>::value || !boost::is_rvalue_reference<From>::value, |
| "binding rvalue references to optional lvalue references is disallowed"); |
| #endif |
| } |
| |
| struct optional_tag {} ; |
| |
| template<class T> |
| class optional_base : public optional_tag |
| { |
| private : |
| |
| typedef |
| #if !BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x564)) |
| BOOST_DEDUCED_TYPENAME |
| #endif |
| ::boost::detail::make_reference_content<T>::type internal_type ; |
| |
| typedef aligned_storage<internal_type> storage_type ; |
| |
| typedef types_when_isnt_ref<T> types_when_not_ref ; |
| typedef types_when_is_ref<T> types_when_ref ; |
| |
| typedef optional_base<T> this_type ; |
| |
| protected : |
| |
| typedef T value_type ; |
| |
| typedef true_type is_reference_tag ; |
| typedef false_type is_not_reference_tag ; |
| |
| typedef BOOST_DEDUCED_TYPENAME is_reference<T>::type is_reference_predicate ; |
| |
| public: |
| typedef BOOST_DEDUCED_TYPENAME conditional<is_reference_predicate::value,types_when_ref,types_when_not_ref>::type types ; |
| |
| protected: |
| typedef BOOST_DEDUCED_TYPENAME types::reference_type reference_type ; |
| typedef BOOST_DEDUCED_TYPENAME types::reference_const_type reference_const_type ; |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| typedef BOOST_DEDUCED_TYPENAME types::rval_reference_type rval_reference_type ; |
| typedef BOOST_DEDUCED_TYPENAME types::reference_type_of_temporary_wrapper reference_type_of_temporary_wrapper ; |
| #endif |
| typedef BOOST_DEDUCED_TYPENAME types::pointer_type pointer_type ; |
| typedef BOOST_DEDUCED_TYPENAME types::pointer_const_type pointer_const_type ; |
| typedef BOOST_DEDUCED_TYPENAME types::argument_type argument_type ; |
| |
| // Creates an optional<T> uninitialized. |
| // No-throw |
| optional_base() |
| : |
| m_initialized(false) {} |
| |
| // Creates an optional<T> uninitialized. |
| // No-throw |
| optional_base ( none_t ) |
| : |
| m_initialized(false) {} |
| |
| // Creates an optional<T> initialized with 'val'. |
| // Can throw if T::T(T const&) does |
| optional_base ( argument_type val ) |
| : |
| m_initialized(false) |
| { |
| construct(val); |
| } |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| // move-construct an optional<T> initialized from an rvalue-ref to 'val'. |
| // Can throw if T::T(T&&) does |
| optional_base ( rval_reference_type val ) |
| : |
| m_initialized(false) |
| { |
| construct( boost::move(val) ); |
| } |
| #endif |
| |
| // Creates an optional<T> initialized with 'val' IFF cond is true, otherwise creates an uninitialized optional<T>. |
| // Can throw if T::T(T const&) does |
| optional_base ( bool cond, argument_type val ) |
| : |
| m_initialized(false) |
| { |
| if ( cond ) |
| construct(val); |
| } |
| |
| // Creates a deep copy of another optional<T> |
| // Can throw if T::T(T const&) does |
| optional_base ( optional_base const& rhs ) |
| : |
| m_initialized(false) |
| { |
| if ( rhs.is_initialized() ) |
| construct(rhs.get_impl()); |
| } |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| // Creates a deep move of another optional<T> |
| // Can throw if T::T(T&&) does |
| optional_base ( optional_base&& rhs ) |
| : |
| m_initialized(false) |
| { |
| if ( rhs.is_initialized() ) |
| construct( boost::move(rhs.get_impl()) ); |
| } |
| #endif |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| |
| template<class Expr, class PtrExpr> |
| explicit optional_base ( Expr&& expr, PtrExpr const* tag ) |
| : |
| m_initialized(false) |
| { |
| construct(boost::forward<Expr>(expr),tag); |
| } |
| |
| #else |
| // This is used for both converting and in-place constructions. |
| // Derived classes use the 'tag' to select the appropriate |
| // implementation (the correct 'construct()' overload) |
| template<class Expr> |
| explicit optional_base ( Expr const& expr, Expr const* tag ) |
| : |
| m_initialized(false) |
| { |
| construct(expr,tag); |
| } |
| |
| #endif |
| |
| |
| // No-throw (assuming T::~T() doesn't) |
| ~optional_base() { destroy() ; } |
| |
| // Assigns from another optional<T> (deep-copies the rhs value) |
| void assign ( optional_base const& rhs ) |
| { |
| if (is_initialized()) |
| { |
| if ( rhs.is_initialized() ) |
| assign_value(rhs.get_impl(), is_reference_predicate() ); |
| else destroy(); |
| } |
| else |
| { |
| if ( rhs.is_initialized() ) |
| construct(rhs.get_impl()); |
| } |
| } |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| // Assigns from another optional<T> (deep-moves the rhs value) |
| void assign ( optional_base&& rhs ) |
| { |
| if (is_initialized()) |
| { |
| if ( rhs.is_initialized() ) |
| assign_value(boost::move(rhs.get_impl()), is_reference_predicate() ); |
| else destroy(); |
| } |
| else |
| { |
| if ( rhs.is_initialized() ) |
| construct(boost::move(rhs.get_impl())); |
| } |
| } |
| #endif |
| |
| // Assigns from another _convertible_ optional<U> (deep-copies the rhs value) |
| template<class U> |
| void assign ( optional<U> const& rhs ) |
| { |
| if (is_initialized()) |
| { |
| if ( rhs.is_initialized() ) |
| #ifndef BOOST_OPTIONAL_CONFIG_RESTORE_ASSIGNMENT_OF_NONCONVERTIBLE_TYPES |
| assign_value(rhs.get(), is_reference_predicate() ); |
| #else |
| assign_value(static_cast<value_type>(rhs.get()), is_reference_predicate() ); |
| #endif |
| |
| else destroy(); |
| } |
| else |
| { |
| if ( rhs.is_initialized() ) |
| #ifndef BOOST_OPTIONAL_CONFIG_RESTORE_ASSIGNMENT_OF_NONCONVERTIBLE_TYPES |
| construct(rhs.get()); |
| #else |
| construct(static_cast<value_type>(rhs.get())); |
| #endif |
| } |
| } |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| // move-assigns from another _convertible_ optional<U> (deep-moves from the rhs value) |
| template<class U> |
| void assign ( optional<U>&& rhs ) |
| { |
| typedef BOOST_DEDUCED_TYPENAME optional<U>::rval_reference_type ref_type; |
| if (is_initialized()) |
| { |
| if ( rhs.is_initialized() ) |
| assign_value(static_cast<ref_type>(rhs.get()), is_reference_predicate() ); |
| else destroy(); |
| } |
| else |
| { |
| if ( rhs.is_initialized() ) |
| construct(static_cast<ref_type>(rhs.get())); |
| } |
| } |
| #endif |
| |
| // Assigns from a T (deep-copies the rhs value) |
| void assign ( argument_type val ) |
| { |
| if (is_initialized()) |
| assign_value(val, is_reference_predicate() ); |
| else construct(val); |
| } |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| // Assigns from a T (deep-moves the rhs value) |
| void assign ( rval_reference_type val ) |
| { |
| if (is_initialized()) |
| assign_value( boost::move(val), is_reference_predicate() ); |
| else construct( boost::move(val) ); |
| } |
| #endif |
| |
| // Assigns from "none", destroying the current value, if any, leaving this UNINITIALIZED |
| // No-throw (assuming T::~T() doesn't) |
| void assign ( none_t ) BOOST_NOEXCEPT { destroy(); } |
| |
| #ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| template<class Expr, class ExprPtr> |
| void assign_expr ( Expr&& expr, ExprPtr const* tag ) |
| { |
| if (is_initialized()) |
| assign_expr_to_initialized(boost::forward<Expr>(expr),tag); |
| else construct(boost::forward<Expr>(expr),tag); |
| } |
| #else |
| template<class Expr> |
| void assign_expr ( Expr const& expr, Expr const* tag ) |
| { |
| if (is_initialized()) |
| assign_expr_to_initialized(expr,tag); |
| else construct(expr,tag); |
| } |
| #endif |
| |
| #endif |
| |
| public : |
| |
| // Destroys the current value, if any, leaving this UNINITIALIZED |
| // No-throw (assuming T::~T() doesn't) |
| void reset() BOOST_NOEXCEPT { destroy(); } |
| |
| // **DEPPRECATED** Replaces the current value -if any- with 'val' |
| void reset ( argument_type val ) { assign(val); } |
| |
| // Returns a pointer to the value if this is initialized, otherwise, |
| // returns NULL. |
| // No-throw |
| pointer_const_type get_ptr() const { return m_initialized ? get_ptr_impl() : 0 ; } |
| pointer_type get_ptr() { return m_initialized ? get_ptr_impl() : 0 ; } |
| |
| bool is_initialized() const { return m_initialized ; } |
| |
| protected : |
| |
| void construct ( argument_type val ) |
| { |
| ::new (m_storage.address()) internal_type(val) ; |
| m_initialized = true ; |
| } |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| void construct ( rval_reference_type val ) |
| { |
| ::new (m_storage.address()) internal_type( types::move(val) ) ; |
| m_initialized = true ; |
| } |
| #endif |
| |
| |
| #if (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) && (!defined BOOST_NO_CXX11_VARIADIC_TEMPLATES) |
| // Constructs in-place |
| // upon exception *this is always uninitialized |
| template<class... Args> |
| void emplace_assign ( Args&&... args ) |
| { |
| destroy(); |
| ::new (m_storage.address()) internal_type( boost::forward<Args>(args)... ); |
| m_initialized = true ; |
| } |
| #elif (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) |
| template<class Arg> |
| void emplace_assign ( Arg&& arg ) |
| { |
| destroy(); |
| ::new (m_storage.address()) internal_type( boost::forward<Arg>(arg) ); |
| m_initialized = true ; |
| } |
| |
| void emplace_assign () |
| { |
| destroy(); |
| ::new (m_storage.address()) internal_type(); |
| m_initialized = true ; |
| } |
| #else |
| template<class Arg> |
| void emplace_assign ( const Arg& arg ) |
| { |
| destroy(); |
| ::new (m_storage.address()) internal_type( arg ); |
| m_initialized = true ; |
| } |
| |
| template<class Arg> |
| void emplace_assign ( Arg& arg ) |
| { |
| destroy(); |
| ::new (m_storage.address()) internal_type( arg ); |
| m_initialized = true ; |
| } |
| |
| void emplace_assign () |
| { |
| destroy(); |
| ::new (m_storage.address()) internal_type(); |
| m_initialized = true ; |
| } |
| #endif |
| |
| #ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| // Constructs in-place using the given factory |
| template<class Expr> |
| void construct ( Expr&& factory, in_place_factory_base const* ) |
| { |
| BOOST_STATIC_ASSERT ( !is_reference_predicate::value ) ; |
| boost_optional_detail::construct<value_type>(factory, m_storage.address()); |
| m_initialized = true ; |
| } |
| |
| // Constructs in-place using the given typed factory |
| template<class Expr> |
| void construct ( Expr&& factory, typed_in_place_factory_base const* ) |
| { |
| BOOST_STATIC_ASSERT ( !is_reference_predicate::value ) ; |
| factory.apply(m_storage.address()) ; |
| m_initialized = true ; |
| } |
| |
| template<class Expr> |
| void assign_expr_to_initialized ( Expr&& factory, in_place_factory_base const* tag ) |
| { |
| destroy(); |
| construct(factory,tag); |
| } |
| |
| // Constructs in-place using the given typed factory |
| template<class Expr> |
| void assign_expr_to_initialized ( Expr&& factory, typed_in_place_factory_base const* tag ) |
| { |
| destroy(); |
| construct(factory,tag); |
| } |
| |
| #else |
| // Constructs in-place using the given factory |
| template<class Expr> |
| void construct ( Expr const& factory, in_place_factory_base const* ) |
| { |
| BOOST_STATIC_ASSERT ( !is_reference_predicate::value ) ; |
| boost_optional_detail::construct<value_type>(factory, m_storage.address()); |
| m_initialized = true ; |
| } |
| |
| // Constructs in-place using the given typed factory |
| template<class Expr> |
| void construct ( Expr const& factory, typed_in_place_factory_base const* ) |
| { |
| BOOST_STATIC_ASSERT ( !is_reference_predicate::value ) ; |
| factory.apply(m_storage.address()) ; |
| m_initialized = true ; |
| } |
| |
| template<class Expr> |
| void assign_expr_to_initialized ( Expr const& factory, in_place_factory_base const* tag ) |
| { |
| destroy(); |
| construct(factory,tag); |
| } |
| |
| // Constructs in-place using the given typed factory |
| template<class Expr> |
| void assign_expr_to_initialized ( Expr const& factory, typed_in_place_factory_base const* tag ) |
| { |
| destroy(); |
| construct(factory,tag); |
| } |
| #endif |
| |
| #endif |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| // Constructs using any expression implicitly convertible to the single argument |
| // of a one-argument T constructor. |
| // Converting constructions of optional<T> from optional<U> uses this function with |
| // 'Expr' being of type 'U' and relying on a converting constructor of T from U. |
| template<class Expr> |
| void construct ( Expr&& expr, void const* ) |
| { |
| new (m_storage.address()) internal_type(boost::forward<Expr>(expr)) ; |
| m_initialized = true ; |
| } |
| |
| // Assigns using a form any expression implicitly convertible to the single argument |
| // of a T's assignment operator. |
| // Converting assignments of optional<T> from optional<U> uses this function with |
| // 'Expr' being of type 'U' and relying on a converting assignment of T from U. |
| template<class Expr> |
| void assign_expr_to_initialized ( Expr&& expr, void const* ) |
| { |
| assign_value(boost::forward<Expr>(expr), is_reference_predicate()); |
| } |
| #else |
| // Constructs using any expression implicitly convertible to the single argument |
| // of a one-argument T constructor. |
| // Converting constructions of optional<T> from optional<U> uses this function with |
| // 'Expr' being of type 'U' and relying on a converting constructor of T from U. |
| template<class Expr> |
| void construct ( Expr const& expr, void const* ) |
| { |
| new (m_storage.address()) internal_type(expr) ; |
| m_initialized = true ; |
| } |
| |
| // Assigns using a form any expression implicitly convertible to the single argument |
| // of a T's assignment operator. |
| // Converting assignments of optional<T> from optional<U> uses this function with |
| // 'Expr' being of type 'U' and relying on a converting assignment of T from U. |
| template<class Expr> |
| void assign_expr_to_initialized ( Expr const& expr, void const* ) |
| { |
| assign_value(expr, is_reference_predicate()); |
| } |
| |
| #endif |
| |
| #ifdef BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION |
| // BCB5.64 (and probably lower versions) workaround. |
| // The in-place factories are supported by means of catch-all constructors |
| // and assignment operators (the functions are parameterized in terms of |
| // an arbitrary 'Expr' type) |
| // This compiler incorrectly resolves the overload set and sinks optional<T> and optional<U> |
| // to the 'Expr'-taking functions even though explicit overloads are present for them. |
| // Thus, the following overload is needed to properly handle the case when the 'lhs' |
| // is another optional. |
| // |
| // For VC<=70 compilers this workaround dosen't work becasue the comnpiler issues and error |
| // instead of choosing the wrong overload |
| // |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| // Notice that 'Expr' will be optional<T> or optional<U> (but not optional_base<..>) |
| template<class Expr> |
| void construct ( Expr&& expr, optional_tag const* ) |
| { |
| if ( expr.is_initialized() ) |
| { |
| // An exception can be thrown here. |
| // It it happens, THIS will be left uninitialized. |
| new (m_storage.address()) internal_type(types::move(expr.get())) ; |
| m_initialized = true ; |
| } |
| } |
| #else |
| // Notice that 'Expr' will be optional<T> or optional<U> (but not optional_base<..>) |
| template<class Expr> |
| void construct ( Expr const& expr, optional_tag const* ) |
| { |
| if ( expr.is_initialized() ) |
| { |
| // An exception can be thrown here. |
| // It it happens, THIS will be left uninitialized. |
| new (m_storage.address()) internal_type(expr.get()) ; |
| m_initialized = true ; |
| } |
| } |
| #endif |
| #endif // defined BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION |
| |
| void assign_value ( argument_type val, is_not_reference_tag ) { get_impl() = val; } |
| void assign_value ( argument_type val, is_reference_tag ) { construct(val); } |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| void assign_value ( rval_reference_type val, is_not_reference_tag ) { get_impl() = static_cast<rval_reference_type>(val); } |
| void assign_value ( rval_reference_type val, is_reference_tag ) { construct( static_cast<rval_reference_type>(val) ); } |
| #endif |
| |
| void destroy() |
| { |
| if ( m_initialized ) |
| destroy_impl(is_reference_predicate()) ; |
| } |
| |
| reference_const_type get_impl() const { return dereference(get_object(), is_reference_predicate() ) ; } |
| reference_type get_impl() { return dereference(get_object(), is_reference_predicate() ) ; } |
| |
| pointer_const_type get_ptr_impl() const { return cast_ptr(get_object(), is_reference_predicate() ) ; } |
| pointer_type get_ptr_impl() { return cast_ptr(get_object(), is_reference_predicate() ) ; } |
| |
| private : |
| |
| // internal_type can be either T or reference_content<T> |
| #if defined(BOOST_OPTIONAL_DETAIL_USE_ATTRIBUTE_MAY_ALIAS) |
| // This workaround is supposed to silence GCC warnings about broken strict aliasing rules |
| internal_type const* get_object() const |
| { |
| union { void const* ap_pvoid; internal_type const* as_ptype; } caster = { m_storage.address() }; |
| return caster.as_ptype; |
| } |
| internal_type * get_object() |
| { |
| union { void* ap_pvoid; internal_type* as_ptype; } caster = { m_storage.address() }; |
| return caster.as_ptype; |
| } |
| #else |
| internal_type const* get_object() const { return static_cast<internal_type const*>(m_storage.address()); } |
| internal_type * get_object() { return static_cast<internal_type *> (m_storage.address()); } |
| #endif |
| |
| // reference_content<T> lacks an implicit conversion to T&, so the following is needed to obtain a proper reference. |
| reference_const_type dereference( internal_type const* p, is_not_reference_tag ) const { return *p ; } |
| reference_type dereference( internal_type* p, is_not_reference_tag ) { return *p ; } |
| reference_const_type dereference( internal_type const* p, is_reference_tag ) const { return p->get() ; } |
| reference_type dereference( internal_type* p, is_reference_tag ) { return p->get() ; } |
| |
| #if BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x581)) |
| void destroy_impl ( is_not_reference_tag ) { get_ptr_impl()->internal_type::~internal_type() ; m_initialized = false ; } |
| #else |
| void destroy_impl ( is_not_reference_tag ) { get_ptr_impl()->~T() ; m_initialized = false ; } |
| #endif |
| |
| void destroy_impl ( is_reference_tag ) { m_initialized = false ; } |
| |
| // If T is of reference type, trying to get a pointer to the held value must result in a compile-time error. |
| // Decent compilers should disallow conversions from reference_content<T>* to T*, but just in case, |
| // the following olverloads are used to filter out the case and guarantee an error in case of T being a reference. |
| pointer_const_type cast_ptr( internal_type const* p, is_not_reference_tag ) const { return p ; } |
| pointer_type cast_ptr( internal_type * p, is_not_reference_tag ) { return p ; } |
| pointer_const_type cast_ptr( internal_type const* p, is_reference_tag ) const { return &p->get() ; } |
| pointer_type cast_ptr( internal_type * p, is_reference_tag ) { return &p->get() ; } |
| |
| bool m_initialized ; |
| storage_type m_storage ; |
| } ; |
| |
| } // namespace optional_detail |
| |
| template<class T> |
| class optional : public optional_detail::optional_base<T> |
| { |
| typedef optional_detail::optional_base<T> base ; |
| |
| public : |
| |
| typedef optional<T> this_type ; |
| |
| typedef BOOST_DEDUCED_TYPENAME base::value_type value_type ; |
| typedef BOOST_DEDUCED_TYPENAME base::reference_type reference_type ; |
| typedef BOOST_DEDUCED_TYPENAME base::reference_const_type reference_const_type ; |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| typedef BOOST_DEDUCED_TYPENAME base::rval_reference_type rval_reference_type ; |
| typedef BOOST_DEDUCED_TYPENAME base::reference_type_of_temporary_wrapper reference_type_of_temporary_wrapper ; |
| #endif |
| typedef BOOST_DEDUCED_TYPENAME base::pointer_type pointer_type ; |
| typedef BOOST_DEDUCED_TYPENAME base::pointer_const_type pointer_const_type ; |
| typedef BOOST_DEDUCED_TYPENAME base::argument_type argument_type ; |
| |
| // Creates an optional<T> uninitialized. |
| // No-throw |
| optional() BOOST_NOEXCEPT : base() {} |
| |
| // Creates an optional<T> uninitialized. |
| // No-throw |
| optional( none_t none_ ) BOOST_NOEXCEPT : base(none_) {} |
| |
| // Creates an optional<T> initialized with 'val'. |
| // Can throw if T::T(T const&) does |
| optional ( argument_type val ) : base(val) {} |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| // Creates an optional<T> initialized with 'move(val)'. |
| // Can throw if T::T(T &&) does |
| optional ( rval_reference_type val ) : base( boost::forward<T>(val) ) |
| {optional_detail::prevent_binding_rvalue_ref_to_optional_lvalue_ref<T, rval_reference_type>();} |
| #endif |
| |
| // Creates an optional<T> initialized with 'val' IFF cond is true, otherwise creates an uninitialized optional. |
| // Can throw if T::T(T const&) does |
| optional ( bool cond, argument_type val ) : base(cond,val) {} |
| |
| // NOTE: MSVC needs templated versions first |
| |
| // Creates a deep copy of another convertible optional<U> |
| // Requires a valid conversion from U to T. |
| // Can throw if T::T(U const&) does |
| template<class U> |
| explicit optional ( optional<U> const& rhs ) |
| : |
| base() |
| { |
| if ( rhs.is_initialized() ) |
| this->construct(rhs.get()); |
| } |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| // Creates a deep move of another convertible optional<U> |
| // Requires a valid conversion from U to T. |
| // Can throw if T::T(U&&) does |
| template<class U> |
| explicit optional ( optional<U> && rhs ) |
| : |
| base() |
| { |
| if ( rhs.is_initialized() ) |
| this->construct( boost::move(rhs.get()) ); |
| } |
| #endif |
| |
| #ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT |
| // Creates an optional<T> with an expression which can be either |
| // (a) An instance of InPlaceFactory (i.e. in_place(a,b,...,n); |
| // (b) An instance of TypedInPlaceFactory ( i.e. in_place<T>(a,b,...,n); |
| // (c) Any expression implicitly convertible to the single type |
| // of a one-argument T's constructor. |
| // (d*) Weak compilers (BCB) might also resolved Expr as optional<T> and optional<U> |
| // even though explicit overloads are present for these. |
| // Depending on the above some T ctor is called. |
| // Can throw if the resolved T ctor throws. |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| |
| |
| template<class Expr> |
| explicit optional ( Expr&& expr, |
| BOOST_DEDUCED_TYPENAME boost::disable_if_c< |
| (boost::is_base_of<optional_detail::optional_tag, BOOST_DEDUCED_TYPENAME boost::decay<Expr>::type>::value) || |
| boost::is_same<BOOST_DEDUCED_TYPENAME boost::decay<Expr>::type, none_t>::value, bool >::type = true |
| ) |
| : base(boost::forward<Expr>(expr),boost::addressof(expr)) |
| {optional_detail::prevent_binding_rvalue_ref_to_optional_lvalue_ref<T, Expr&&>();} |
| |
| #else |
| template<class Expr> |
| explicit optional ( Expr const& expr ) : base(expr,boost::addressof(expr)) {} |
| #endif // !defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| #endif // !defined BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT |
| |
| // Creates a deep copy of another optional<T> |
| // Can throw if T::T(T const&) does |
| optional ( optional const& rhs ) : base( static_cast<base const&>(rhs) ) {} |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| // Creates a deep move of another optional<T> |
| // Can throw if T::T(T&&) does |
| optional ( optional && rhs ) |
| BOOST_NOEXCEPT_IF(::boost::is_nothrow_move_constructible<T>::value) |
| : base( boost::move(rhs) ) |
| {} |
| |
| #endif |
| // No-throw (assuming T::~T() doesn't) |
| ~optional() {} |
| |
| #if !defined(BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT) && !defined(BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION) |
| // Assigns from an expression. See corresponding constructor. |
| // Basic Guarantee: If the resolved T ctor throws, this is left UNINITIALIZED |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| |
| template<class Expr> |
| BOOST_DEDUCED_TYPENAME boost::disable_if_c< |
| boost::is_base_of<optional_detail::optional_tag, BOOST_DEDUCED_TYPENAME boost::decay<Expr>::type>::value || |
| boost::is_same<BOOST_DEDUCED_TYPENAME boost::decay<Expr>::type, none_t>::value, |
| optional& |
| >::type |
| operator= ( Expr&& expr ) |
| { |
| optional_detail::prevent_binding_rvalue_ref_to_optional_lvalue_ref<T, Expr&&>(); |
| this->assign_expr(boost::forward<Expr>(expr),boost::addressof(expr)); |
| return *this ; |
| } |
| |
| #else |
| template<class Expr> |
| optional& operator= ( Expr const& expr ) |
| { |
| this->assign_expr(expr,boost::addressof(expr)); |
| return *this ; |
| } |
| #endif // !defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| #endif // !defined(BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT) && !defined(BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION) |
| |
| // Copy-assigns from another convertible optional<U> (converts && deep-copies the rhs value) |
| // Requires a valid conversion from U to T. |
| // Basic Guarantee: If T::T( U const& ) throws, this is left UNINITIALIZED |
| template<class U> |
| optional& operator= ( optional<U> const& rhs ) |
| { |
| this->assign(rhs); |
| return *this ; |
| } |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| // Move-assigns from another convertible optional<U> (converts && deep-moves the rhs value) |
| // Requires a valid conversion from U to T. |
| // Basic Guarantee: If T::T( U && ) throws, this is left UNINITIALIZED |
| template<class U> |
| optional& operator= ( optional<U> && rhs ) |
| { |
| this->assign(boost::move(rhs)); |
| return *this ; |
| } |
| #endif |
| |
| // Assigns from another optional<T> (deep-copies the rhs value) |
| // Basic Guarantee: If T::T( T const& ) throws, this is left UNINITIALIZED |
| // (NOTE: On BCB, this operator is not actually called and left is left UNMODIFIED in case of a throw) |
| optional& operator= ( optional const& rhs ) |
| { |
| this->assign( static_cast<base const&>(rhs) ) ; |
| return *this ; |
| } |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| // Assigns from another optional<T> (deep-moves the rhs value) |
| optional& operator= ( optional && rhs ) |
| BOOST_NOEXCEPT_IF(::boost::is_nothrow_move_constructible<T>::value && ::boost::is_nothrow_move_assignable<T>::value) |
| { |
| this->assign( static_cast<base &&>(rhs) ) ; |
| return *this ; |
| } |
| #endif |
| |
| // Assigns from a T (deep-copies the rhs value) |
| // Basic Guarantee: If T::( T const& ) throws, this is left UNINITIALIZED |
| optional& operator= ( argument_type val ) |
| { |
| this->assign( val ) ; |
| return *this ; |
| } |
| |
| #ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| // Assigns from a T (deep-moves the rhs value) |
| optional& operator= ( rval_reference_type val ) |
| { |
| optional_detail::prevent_binding_rvalue_ref_to_optional_lvalue_ref<T, rval_reference_type>(); |
| this->assign( boost::move(val) ) ; |
| return *this ; |
| } |
| #endif |
| |
| // Assigns from a "none" |
| // Which destroys the current value, if any, leaving this UNINITIALIZED |
| // No-throw (assuming T::~T() doesn't) |
| optional& operator= ( none_t none_ ) BOOST_NOEXCEPT |
| { |
| this->assign( none_ ) ; |
| return *this ; |
| } |
| |
| #if (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) && (!defined BOOST_NO_CXX11_VARIADIC_TEMPLATES) |
| // Constructs in-place |
| // upon exception *this is always uninitialized |
| template<class... Args> |
| void emplace ( Args&&... args ) |
| { |
| this->emplace_assign( boost::forward<Args>(args)... ); |
| } |
| #elif (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) |
| template<class Arg> |
| void emplace ( Arg&& arg ) |
| { |
| this->emplace_assign( boost::forward<Arg>(arg) ); |
| } |
| |
| void emplace () |
| { |
| this->emplace_assign(); |
| } |
| #else |
| template<class Arg> |
| void emplace ( const Arg& arg ) |
| { |
| this->emplace_assign( arg ); |
| } |
| |
| template<class Arg> |
| void emplace ( Arg& arg ) |
| { |
| this->emplace_assign( arg ); |
| } |
| |
| void emplace () |
| { |
| this->emplace_assign(); |
| } |
| #endif |
| |
| void swap( optional & arg ) |
| BOOST_NOEXCEPT_IF(::boost::is_nothrow_move_constructible<T>::value && ::boost::is_nothrow_move_assignable<T>::value) |
| { |
| // allow for Koenig lookup |
| boost::swap(*this, arg); |
| } |
| |
| |
| // Returns a reference to the value if this is initialized, otherwise, |
| // the behaviour is UNDEFINED |
| // No-throw |
| reference_const_type get() const { BOOST_ASSERT(this->is_initialized()) ; return this->get_impl(); } |
| reference_type get() { BOOST_ASSERT(this->is_initialized()) ; return this->get_impl(); } |
| |
| // Returns a copy of the value if this is initialized, 'v' otherwise |
| reference_const_type get_value_or ( reference_const_type v ) const { return this->is_initialized() ? get() : v ; } |
| reference_type get_value_or ( reference_type v ) { return this->is_initialized() ? get() : v ; } |
| |
| // Returns a pointer to the value if this is initialized, otherwise, |
| // the behaviour is UNDEFINED |
| // No-throw |
| pointer_const_type operator->() const { BOOST_ASSERT(this->is_initialized()) ; return this->get_ptr_impl() ; } |
| pointer_type operator->() { BOOST_ASSERT(this->is_initialized()) ; return this->get_ptr_impl() ; } |
| |
| // Returns a reference to the value if this is initialized, otherwise, |
| // the behaviour is UNDEFINED |
| // No-throw |
| #if (!defined BOOST_NO_CXX11_REF_QUALIFIERS) && (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) |
| reference_const_type operator *() const& { return this->get() ; } |
| reference_type operator *() & { return this->get() ; } |
| reference_type_of_temporary_wrapper operator *() && { return base::types::move(this->get()) ; } |
| #else |
| reference_const_type operator *() const { return this->get() ; } |
| reference_type operator *() { return this->get() ; } |
| #endif // !defined BOOST_NO_CXX11_REF_QUALIFIERS |
| |
| #if (!defined BOOST_NO_CXX11_REF_QUALIFIERS) && (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) |
| reference_const_type value() const& |
| { |
| if (this->is_initialized()) |
| return this->get() ; |
| else |
| throw_exception(bad_optional_access()); |
| } |
| |
| reference_type value() & |
| { |
| if (this->is_initialized()) |
| return this->get() ; |
| else |
| throw_exception(bad_optional_access()); |
| } |
| |
| reference_type_of_temporary_wrapper value() && |
| { |
| if (this->is_initialized()) |
| return base::types::move(this->get()) ; |
| else |
| throw_exception(bad_optional_access()); |
| } |
| |
| #else |
| reference_const_type value() const |
| { |
| if (this->is_initialized()) |
| return this->get() ; |
| else |
| throw_exception(bad_optional_access()); |
| } |
| |
| reference_type value() |
| { |
| if (this->is_initialized()) |
| return this->get() ; |
| else |
| throw_exception(bad_optional_access()); |
| } |
| #endif |
| |
| |
| #ifndef BOOST_NO_CXX11_REF_QUALIFIERS |
| template <class U> |
| value_type value_or ( U&& v ) const& |
| { |
| if (this->is_initialized()) |
| return get(); |
| else |
| return boost::forward<U>(v); |
| } |
| |
| template <class U> |
| value_type value_or ( U&& v ) && |
| { |
| if (this->is_initialized()) |
| return base::types::move(get()); |
| else |
| return boost::forward<U>(v); |
| } |
| #elif !defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES |
| template <class U> |
| value_type value_or ( U&& v ) const |
| { |
| if (this->is_initialized()) |
| return get(); |
| else |
| return boost::forward<U>(v); |
| } |
| #else |
| template <class U> |
| value_type value_or ( U const& v ) const |
| { |
| if (this->is_initialized()) |
| return get(); |
| else |
| return v; |
| } |
| |
| template <class U> |
| value_type value_or ( U& v ) const |
| { |
| if (this->is_initialized()) |
| return get(); |
| else |
| return v; |
| } |
| #endif |
| |
| |
| #ifndef BOOST_NO_CXX11_REF_QUALIFIERS |
| template <typename F> |
| value_type value_or_eval ( F f ) const& |
| { |
| if (this->is_initialized()) |
| return get(); |
| else |
| return f(); |
| } |
| |
| template <typename F> |
| value_type value_or_eval ( F f ) && |
| { |
| if (this->is_initialized()) |
| return base::types::move(get()); |
| else |
| return f(); |
| } |
| #else |
| template <typename F> |
| value_type value_or_eval ( F f ) const |
| { |
| if (this->is_initialized()) |
| return get(); |
| else |
| return f(); |
| } |
| #endif |
| |
| bool operator!() const BOOST_NOEXCEPT { return !this->is_initialized() ; } |
| |
| BOOST_EXPLICIT_OPERATOR_BOOL_NOEXCEPT() |
| } ; |
| |
| } // namespace boost |
| |
| |
| #endif // header guard |
