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1606 lines
47 KiB
1606 lines
47 KiB
// Copyright (C) 2003, 2008 Fernando Luis Cacciola Carballal.
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// Copyright (C) 2014 - 2018 Andrzej Krzemienski.
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//
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// Use, modification, and distribution is subject to the Boost Software
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// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//
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// See http://www.boost.org/libs/optional for documentation.
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//
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// You are welcome to contact the author at:
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// fernando_cacciola@hotmail.com
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//
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// Revisions:
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// 27 Apr 2008 (improved swap) Fernando Cacciola, Niels Dekker, Thorsten Ottosen
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// 05 May 2014 (Added move semantics) Andrzej Krzemienski
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//
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#ifndef BOOST_OPTIONAL_OPTIONAL_FLC_19NOV2002_HPP
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#define BOOST_OPTIONAL_OPTIONAL_FLC_19NOV2002_HPP
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#include <new>
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#include <iosfwd>
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#ifdef BOOST_OPTIONAL_DETAIL_USE_STD_TYPE_TRAITS
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# include <type_traits>
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#endif
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#include <boost/assert.hpp>
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#include <boost/core/addressof.hpp>
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#include <boost/core/enable_if.hpp>
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#include <boost/core/explicit_operator_bool.hpp>
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#include <boost/core/swap.hpp>
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#include <boost/optional/bad_optional_access.hpp>
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#include <boost/static_assert.hpp>
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#include <boost/throw_exception.hpp>
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#include <boost/type.hpp>
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#include <boost/type_traits/alignment_of.hpp>
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#include <boost/type_traits/conditional.hpp>
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#include <boost/type_traits/has_nothrow_constructor.hpp>
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#include <boost/type_traits/type_with_alignment.hpp>
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#include <boost/type_traits/remove_const.hpp>
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#include <boost/type_traits/remove_reference.hpp>
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#include <boost/type_traits/decay.hpp>
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#include <boost/type_traits/is_base_of.hpp>
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#include <boost/type_traits/is_const.hpp>
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#include <boost/type_traits/is_constructible.hpp>
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#include <boost/type_traits/is_lvalue_reference.hpp>
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#include <boost/type_traits/is_nothrow_move_assignable.hpp>
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#include <boost/type_traits/is_nothrow_move_constructible.hpp>
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#include <boost/type_traits/is_rvalue_reference.hpp>
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#include <boost/type_traits/is_same.hpp>
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#include <boost/type_traits/is_volatile.hpp>
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#include <boost/type_traits/is_scalar.hpp>
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#include <boost/move/utility.hpp>
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#include <boost/none.hpp>
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#include <boost/utility/compare_pointees.hpp>
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#include <boost/utility/result_of.hpp>
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#include <boost/optional/optional_fwd.hpp>
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#include <boost/optional/detail/optional_config.hpp>
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#include <boost/optional/detail/optional_factory_support.hpp>
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#include <boost/optional/detail/optional_aligned_storage.hpp>
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namespace boost { namespace optional_detail {
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template <typename T>
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struct optional_value_type
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{
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};
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template <typename T>
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struct optional_value_type< ::boost::optional<T> >
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{
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typedef T type;
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};
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}} // namespace boost::optional_detail
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#ifdef BOOST_OPTIONAL_CONFIG_USE_OLD_IMPLEMENTATION_OF_OPTIONAL
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#include <boost/optional/detail/old_optional_implementation.hpp>
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#else
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namespace boost {
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namespace optional_ns {
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// a tag for in-place initialization of contained value
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struct in_place_init_t
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{
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struct init_tag{};
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explicit in_place_init_t(init_tag){}
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};
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const in_place_init_t in_place_init ((in_place_init_t::init_tag()));
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// a tag for conditional in-place initialization of contained value
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struct in_place_init_if_t
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{
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struct init_tag{};
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explicit in_place_init_if_t(init_tag){}
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};
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const in_place_init_if_t in_place_init_if ((in_place_init_if_t::init_tag()));
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} // namespace optional_ns
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using optional_ns::in_place_init_t;
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using optional_ns::in_place_init;
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using optional_ns::in_place_init_if_t;
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using optional_ns::in_place_init_if;
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namespace optional_detail {
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struct init_value_tag {};
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struct optional_tag {};
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template<class T>
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class optional_base : public optional_tag
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{
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private :
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typedef aligned_storage<T> storage_type ;
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typedef optional_base<T> this_type ;
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protected :
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typedef T value_type ;
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protected:
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typedef T & reference_type ;
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typedef T const& reference_const_type ;
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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typedef T && rval_reference_type ;
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typedef T && reference_type_of_temporary_wrapper ;
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#endif
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typedef T * pointer_type ;
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typedef T const* pointer_const_type ;
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typedef T const& argument_type ;
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// Creates an optional<T> uninitialized.
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// No-throw
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optional_base()
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:
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m_initialized(false) {}
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// Creates an optional<T> uninitialized.
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// No-throw
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optional_base ( none_t )
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:
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m_initialized(false) {}
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// Creates an optional<T> initialized with 'val'.
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// Can throw if T::T(T const&) does
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optional_base ( init_value_tag, argument_type val )
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:
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m_initialized(false)
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{
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construct(val);
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}
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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// move-construct an optional<T> initialized from an rvalue-ref to 'val'.
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// Can throw if T::T(T&&) does
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optional_base ( init_value_tag, rval_reference_type val )
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:
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m_initialized(false)
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{
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construct( boost::move(val) );
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}
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#endif
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// Creates an optional<T> initialized with 'val' IFF cond is true, otherwise creates an uninitialized optional<T>.
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// Can throw if T::T(T const&) does
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optional_base ( bool cond, argument_type val )
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:
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m_initialized(false)
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{
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if ( cond )
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construct(val);
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}
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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// Creates an optional<T> initialized with 'move(val)' IFF cond is true, otherwise creates an uninitialized optional<T>.
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// Can throw if T::T(T &&) does
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optional_base ( bool cond, rval_reference_type val )
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:
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m_initialized(false)
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{
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if ( cond )
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construct(boost::move(val));
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}
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#endif
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// Creates a deep copy of another optional<T>
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// Can throw if T::T(T const&) does
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optional_base ( optional_base const& rhs )
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:
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m_initialized(false)
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{
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if ( rhs.is_initialized() )
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construct(rhs.get_impl());
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}
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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// Creates a deep move of another optional<T>
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// Can throw if T::T(T&&) does
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optional_base ( optional_base&& rhs )
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BOOST_NOEXCEPT_IF(::boost::is_nothrow_move_constructible<T>::value)
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:
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m_initialized(false)
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{
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if ( rhs.is_initialized() )
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construct( boost::move(rhs.get_impl()) );
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}
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#endif
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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template<class Expr, class PtrExpr>
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explicit optional_base ( Expr&& expr, PtrExpr const* tag )
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:
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m_initialized(false)
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{
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construct(boost::forward<Expr>(expr),tag);
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}
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#else
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// This is used for both converting and in-place constructions.
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// Derived classes use the 'tag' to select the appropriate
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// implementation (the correct 'construct()' overload)
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template<class Expr>
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explicit optional_base ( Expr const& expr, Expr const* tag )
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:
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m_initialized(false)
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{
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construct(expr,tag);
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}
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#endif
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optional_base& operator= ( optional_base const& rhs )
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{
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this->assign(rhs);
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return *this;
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}
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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optional_base& operator= ( optional_base && rhs )
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BOOST_NOEXCEPT_IF(::boost::is_nothrow_move_constructible<T>::value && ::boost::is_nothrow_move_assignable<T>::value)
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{
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this->assign(static_cast<optional_base&&>(rhs));
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return *this;
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}
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#endif
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// No-throw (assuming T::~T() doesn't)
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~optional_base() { destroy() ; }
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// Assigns from another optional<T> (deep-copies the rhs value)
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void assign ( optional_base const& rhs )
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{
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if (is_initialized())
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{
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if ( rhs.is_initialized() )
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assign_value(rhs.get_impl());
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else destroy();
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}
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else
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{
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if ( rhs.is_initialized() )
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construct(rhs.get_impl());
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}
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}
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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// Assigns from another optional<T> (deep-moves the rhs value)
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void assign ( optional_base&& rhs )
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{
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if (is_initialized())
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{
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if ( rhs.is_initialized() )
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assign_value( boost::move(rhs.get_impl()) );
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else destroy();
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}
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else
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{
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if ( rhs.is_initialized() )
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construct(boost::move(rhs.get_impl()));
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}
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}
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#endif
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// Assigns from another _convertible_ optional<U> (deep-copies the rhs value)
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template<class U>
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void assign ( optional<U> const& rhs )
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{
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if (is_initialized())
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{
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if ( rhs.is_initialized() )
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#ifndef BOOST_OPTIONAL_CONFIG_RESTORE_ASSIGNMENT_OF_NONCONVERTIBLE_TYPES
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assign_value( rhs.get() );
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#else
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assign_value( static_cast<value_type>(rhs.get()) );
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#endif
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else destroy();
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}
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else
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{
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if ( rhs.is_initialized() )
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#ifndef BOOST_OPTIONAL_CONFIG_RESTORE_ASSIGNMENT_OF_NONCONVERTIBLE_TYPES
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construct(rhs.get());
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#else
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construct(static_cast<value_type>(rhs.get()));
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#endif
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}
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}
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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// move-assigns from another _convertible_ optional<U> (deep-moves from the rhs value)
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template<class U>
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void assign ( optional<U>&& rhs )
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{
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typedef BOOST_DEDUCED_TYPENAME optional<U>::rval_reference_type ref_type;
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if (is_initialized())
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{
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if ( rhs.is_initialized() )
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assign_value( static_cast<ref_type>(rhs.get()) );
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else destroy();
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}
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else
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{
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if ( rhs.is_initialized() )
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construct(static_cast<ref_type>(rhs.get()));
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}
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}
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#endif
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// Assigns from a T (deep-copies the rhs value)
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void assign ( argument_type val )
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{
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if (is_initialized())
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assign_value(val);
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else construct(val);
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}
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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// Assigns from a T (deep-moves the rhs value)
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void assign ( rval_reference_type val )
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{
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if (is_initialized())
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assign_value( boost::move(val) );
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else construct( boost::move(val) );
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}
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#endif
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// Assigns from "none", destroying the current value, if any, leaving this UNINITIALIZED
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// No-throw (assuming T::~T() doesn't)
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void assign ( none_t ) BOOST_NOEXCEPT { destroy(); }
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#ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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template<class Expr, class ExprPtr>
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void assign_expr ( Expr&& expr, ExprPtr const* tag )
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{
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if (is_initialized())
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assign_expr_to_initialized(boost::forward<Expr>(expr),tag);
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else construct(boost::forward<Expr>(expr),tag);
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}
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#else
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template<class Expr>
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void assign_expr ( Expr const& expr, Expr const* tag )
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{
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if (is_initialized())
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assign_expr_to_initialized(expr,tag);
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else construct(expr,tag);
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}
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#endif
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#endif
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public :
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// Destroys the current value, if any, leaving this UNINITIALIZED
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// No-throw (assuming T::~T() doesn't)
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void reset() BOOST_NOEXCEPT { destroy(); }
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// **DEPPRECATED** Replaces the current value -if any- with 'val'
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void reset ( argument_type val ) { assign(val); }
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// Returns a pointer to the value if this is initialized, otherwise,
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// returns NULL.
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// No-throw
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pointer_const_type get_ptr() const { return m_initialized ? get_ptr_impl() : 0 ; }
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pointer_type get_ptr() { return m_initialized ? get_ptr_impl() : 0 ; }
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bool is_initialized() const BOOST_NOEXCEPT { return m_initialized ; }
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protected :
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void construct ( argument_type val )
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{
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::new (m_storage.address()) value_type(val) ;
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m_initialized = true ;
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}
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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void construct ( rval_reference_type val )
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{
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::new (m_storage.address()) value_type( boost::move(val) ) ;
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m_initialized = true ;
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}
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#endif
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#if (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) && (!defined BOOST_NO_CXX11_VARIADIC_TEMPLATES)
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// Constructs in-place
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// upon exception *this is always uninitialized
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template<class... Args>
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void construct ( in_place_init_t, Args&&... args )
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{
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::new (m_storage.address()) value_type( boost::forward<Args>(args)... ) ;
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m_initialized = true ;
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}
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template<class... Args>
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void emplace_assign ( Args&&... args )
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{
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destroy();
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construct(in_place_init, boost::forward<Args>(args)...);
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}
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template<class... Args>
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explicit optional_base ( in_place_init_t, Args&&... args )
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:
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m_initialized(false)
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{
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construct(in_place_init, boost::forward<Args>(args)...);
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}
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template<class... Args>
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explicit optional_base ( in_place_init_if_t, bool cond, Args&&... args )
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:
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m_initialized(false)
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{
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if ( cond )
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construct(in_place_init, boost::forward<Args>(args)...);
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}
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#elif (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES)
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template<class Arg>
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void construct ( in_place_init_t, Arg&& arg )
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{
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::new (m_storage.address()) value_type( boost::forward<Arg>(arg) );
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m_initialized = true ;
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}
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void construct ( in_place_init_t )
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{
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::new (m_storage.address()) value_type();
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m_initialized = true ;
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}
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template<class Arg>
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void emplace_assign ( Arg&& arg )
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{
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destroy();
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construct(in_place_init, boost::forward<Arg>(arg)) ;
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}
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void emplace_assign ()
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{
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destroy();
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construct(in_place_init) ;
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}
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template<class Arg>
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explicit optional_base ( in_place_init_t, Arg&& arg )
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:
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m_initialized(false)
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{
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construct(in_place_init, boost::forward<Arg>(arg));
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}
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explicit optional_base ( in_place_init_t )
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:
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m_initialized(false)
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{
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construct(in_place_init);
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}
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template<class Arg>
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explicit optional_base ( in_place_init_if_t, bool cond, Arg&& arg )
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:
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m_initialized(false)
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{
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if ( cond )
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construct(in_place_init, boost::forward<Arg>(arg));
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}
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explicit optional_base ( in_place_init_if_t, bool cond )
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:
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m_initialized(false)
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{
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if ( cond )
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construct(in_place_init);
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}
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#else
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template<class Arg>
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void construct ( in_place_init_t, const Arg& arg )
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{
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::new (m_storage.address()) value_type( arg );
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m_initialized = true ;
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}
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template<class Arg>
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void construct ( in_place_init_t, Arg& arg )
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{
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::new (m_storage.address()) value_type( arg );
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m_initialized = true ;
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}
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void construct ( in_place_init_t )
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{
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::new (m_storage.address()) value_type();
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m_initialized = true ;
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}
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template<class Arg>
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void emplace_assign ( const Arg& arg )
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{
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destroy();
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construct(in_place_init, arg);
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}
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|
|
|
template<class Arg>
|
|
void emplace_assign ( Arg& arg )
|
|
{
|
|
destroy();
|
|
construct(in_place_init, arg);
|
|
}
|
|
|
|
void emplace_assign ()
|
|
{
|
|
destroy();
|
|
construct(in_place_init);
|
|
}
|
|
|
|
template<class Arg>
|
|
explicit optional_base ( in_place_init_t, const Arg& arg )
|
|
: m_initialized(false)
|
|
{
|
|
construct(in_place_init, arg);
|
|
}
|
|
|
|
template<class Arg>
|
|
explicit optional_base ( in_place_init_t, Arg& arg )
|
|
: m_initialized(false)
|
|
{
|
|
construct(in_place_init, arg);
|
|
}
|
|
|
|
explicit optional_base ( in_place_init_t )
|
|
: m_initialized(false)
|
|
{
|
|
construct(in_place_init);
|
|
}
|
|
|
|
template<class Arg>
|
|
explicit optional_base ( in_place_init_if_t, bool cond, const Arg& arg )
|
|
: m_initialized(false)
|
|
{
|
|
if ( cond )
|
|
construct(in_place_init, arg);
|
|
}
|
|
|
|
template<class Arg>
|
|
explicit optional_base ( in_place_init_if_t, bool cond, Arg& arg )
|
|
: m_initialized(false)
|
|
{
|
|
if ( cond )
|
|
construct(in_place_init, arg);
|
|
}
|
|
|
|
explicit optional_base ( in_place_init_if_t, bool cond )
|
|
: m_initialized(false)
|
|
{
|
|
if ( cond )
|
|
construct(in_place_init);
|
|
}
|
|
#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_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* )
|
|
{
|
|
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_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* )
|
|
{
|
|
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()) value_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) );
|
|
}
|
|
#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()) value_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);
|
|
}
|
|
|
|
#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()) value_type(boost::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()) value_type(expr.get()) ;
|
|
m_initialized = true ;
|
|
}
|
|
}
|
|
#endif
|
|
#endif // defined BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION
|
|
|
|
void assign_value ( argument_type val ) { get_impl() = val; }
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
|
void assign_value ( rval_reference_type val ) { get_impl() = static_cast<rval_reference_type>(val); }
|
|
#endif
|
|
|
|
void destroy()
|
|
{
|
|
if ( m_initialized )
|
|
destroy_impl() ;
|
|
}
|
|
|
|
reference_const_type get_impl() const { return m_storage.ref() ; }
|
|
reference_type get_impl() { return m_storage.ref() ; }
|
|
|
|
pointer_const_type get_ptr_impl() const { return m_storage.ptr_ref(); }
|
|
pointer_type get_ptr_impl() { return m_storage.ptr_ref(); }
|
|
|
|
private :
|
|
|
|
#if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1900))
|
|
void destroy_impl ( ) { m_storage.ptr_ref()->~T() ; m_initialized = false ; }
|
|
#else
|
|
void destroy_impl ( ) { m_storage.ref().T::~T() ; m_initialized = false ; }
|
|
#endif
|
|
|
|
bool m_initialized ;
|
|
storage_type m_storage ;
|
|
} ;
|
|
|
|
#include <boost/optional/detail/optional_trivially_copyable_base.hpp>
|
|
|
|
// definition of metafunction is_optional_val_init_candidate
|
|
template <typename U>
|
|
struct is_optional_related
|
|
: boost::conditional< boost::is_base_of<optional_detail::optional_tag, BOOST_DEDUCED_TYPENAME boost::decay<U>::type>::value
|
|
|| boost::is_same<BOOST_DEDUCED_TYPENAME boost::decay<U>::type, none_t>::value
|
|
|| boost::is_same<BOOST_DEDUCED_TYPENAME boost::decay<U>::type, in_place_init_t>::value
|
|
|| boost::is_same<BOOST_DEDUCED_TYPENAME boost::decay<U>::type, in_place_init_if_t>::value,
|
|
boost::true_type, boost::false_type>::type
|
|
{};
|
|
|
|
#if !defined(BOOST_OPTIONAL_DETAIL_NO_IS_CONSTRUCTIBLE_TRAIT)
|
|
|
|
template <typename T, typename U>
|
|
struct is_convertible_to_T_or_factory
|
|
: boost::conditional< boost::is_base_of<boost::in_place_factory_base, BOOST_DEDUCED_TYPENAME boost::decay<U>::type>::value
|
|
|| boost::is_base_of<boost::typed_in_place_factory_base, BOOST_DEDUCED_TYPENAME boost::decay<U>::type>::value
|
|
|| (boost::is_constructible<T, U&&>::value && !boost::is_same<T, BOOST_DEDUCED_TYPENAME boost::decay<U>::type>::value)
|
|
, boost::true_type, boost::false_type>::type
|
|
{};
|
|
|
|
template <typename T, typename U>
|
|
struct is_optional_constructible : boost::is_constructible<T, U>
|
|
{};
|
|
|
|
#else
|
|
|
|
template <typename, typename>
|
|
struct is_convertible_to_T_or_factory : boost::true_type
|
|
{};
|
|
|
|
template <typename T, typename U>
|
|
struct is_optional_constructible : boost::true_type
|
|
{};
|
|
|
|
#endif // is_convertible condition
|
|
|
|
template <typename T, typename U, bool = is_optional_related<U>::value>
|
|
struct is_optional_val_init_candidate
|
|
: boost::false_type
|
|
{};
|
|
|
|
template <typename T, typename U>
|
|
struct is_optional_val_init_candidate<T, U, false>
|
|
: boost::conditional< is_convertible_to_T_or_factory<T, U>::value
|
|
, boost::true_type, boost::false_type>::type
|
|
{};
|
|
|
|
} // namespace optional_detail
|
|
|
|
namespace optional_config {
|
|
|
|
template <typename T>
|
|
struct optional_uses_direct_storage_for
|
|
: boost::conditional<(boost::is_scalar<T>::value && !boost::is_const<T>::value && !boost::is_volatile<T>::value)
|
|
, boost::true_type, boost::false_type>::type
|
|
{};
|
|
|
|
} // namespace optional_config
|
|
|
|
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_DIRECT_STORAGE_SPEC
|
|
# define BOOST_OPTIONAL_BASE_TYPE(T) boost::conditional< optional_config::optional_uses_direct_storage_for<T>::value, \
|
|
optional_detail::tc_optional_base<T>, \
|
|
optional_detail::optional_base<T> \
|
|
>::type
|
|
#else
|
|
# define BOOST_OPTIONAL_BASE_TYPE(T) optional_detail::optional_base<T>
|
|
#endif
|
|
|
|
template<class T>
|
|
class optional
|
|
: public BOOST_OPTIONAL_BASE_TYPE(T)
|
|
{
|
|
typedef typename BOOST_OPTIONAL_BASE_TYPE(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(optional_detail::init_value_tag(), 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(optional_detail::init_value_tag(), boost::forward<T>(val))
|
|
{}
|
|
#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) {}
|
|
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
|
/// Creates an optional<T> initialized with 'val' IFF cond is true, otherwise creates an uninitialized optional.
|
|
// Can throw if T::T(T &&) does
|
|
optional ( bool cond, rval_reference_type val ) : base( cond, boost::forward<T>(val) )
|
|
{}
|
|
#endif
|
|
|
|
// 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
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_SFINAE_FRIENDLY_CONSTRUCTORS
|
|
,BOOST_DEDUCED_TYPENAME boost::enable_if< optional_detail::is_optional_constructible<T, U const&>, bool>::type = true
|
|
#endif
|
|
)
|
|
:
|
|
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
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_SFINAE_FRIENDLY_CONSTRUCTORS
|
|
,BOOST_DEDUCED_TYPENAME boost::enable_if< optional_detail::is_optional_constructible<T, U>, bool>::type = true
|
|
#endif
|
|
)
|
|
:
|
|
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::enable_if< optional_detail::is_optional_val_init_candidate<T, Expr>, bool>::type = true
|
|
)
|
|
: base(boost::forward<Expr>(expr),boost::addressof(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
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_DEFAULTED_MOVE_FUNCTIONS
|
|
optional ( optional const& ) = default;
|
|
#else
|
|
optional ( optional const& rhs ) : base( static_cast<base const&>(rhs) ) {}
|
|
#endif
|
|
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
|
// Creates a deep move of another optional<T>
|
|
// Can throw if T::T(T&&) does
|
|
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_DEFAULTED_MOVE_FUNCTIONS
|
|
optional ( optional && ) = default;
|
|
#else
|
|
optional ( optional && rhs )
|
|
BOOST_NOEXCEPT_IF(::boost::is_nothrow_move_constructible<T>::value)
|
|
: base( boost::move(rhs) )
|
|
{}
|
|
#endif
|
|
|
|
#endif
|
|
|
|
#if BOOST_WORKAROUND(_MSC_VER, <= 1600)
|
|
// On old MSVC compilers the implicitly declared dtor is not called
|
|
~optional() {}
|
|
#endif
|
|
|
|
|
|
#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::enable_if<optional_detail::is_optional_val_init_candidate<T, Expr>, optional&>::type
|
|
operator= ( Expr&& 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)
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_DEFAULTED_MOVE_FUNCTIONS
|
|
optional& operator= ( optional const& rhs ) = default;
|
|
#else
|
|
optional& operator= ( optional const& rhs )
|
|
{
|
|
this->assign( static_cast<base const&>(rhs) ) ;
|
|
return *this ;
|
|
}
|
|
#endif
|
|
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
|
// Assigns from another optional<T> (deep-moves the rhs value)
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_DEFAULTED_MOVE_FUNCTIONS
|
|
optional& operator= ( optional && ) = default;
|
|
#else
|
|
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
|
|
|
|
#endif // BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
|
|
|
#ifndef BOOST_NO_CXX11_UNIFIED_INITIALIZATION_SYNTAX
|
|
|
|
// Assigns from a T (deep-moves/copies the rhs value)
|
|
template <typename T_>
|
|
BOOST_DEDUCED_TYPENAME boost::enable_if<boost::is_same<T, BOOST_DEDUCED_TYPENAME boost::decay<T_>::type>, optional&>::type
|
|
operator= ( T_&& val )
|
|
{
|
|
this->assign( boost::forward<T_>(val) ) ;
|
|
return *this ;
|
|
}
|
|
|
|
#else
|
|
|
|
// 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 )
|
|
{
|
|
this->assign( boost::move(val) ) ;
|
|
return *this ;
|
|
}
|
|
#endif
|
|
|
|
#endif // BOOST_NO_CXX11_UNIFIED_INITIALIZATION_SYNTAX
|
|
|
|
// 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)... );
|
|
}
|
|
|
|
template<class... Args>
|
|
explicit optional ( in_place_init_t, Args&&... args )
|
|
: base( in_place_init, boost::forward<Args>(args)... )
|
|
{}
|
|
|
|
template<class... Args>
|
|
explicit optional ( in_place_init_if_t, bool cond, Args&&... args )
|
|
: base( in_place_init_if, cond, 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();
|
|
}
|
|
|
|
template<class Args>
|
|
explicit optional ( in_place_init_t, Args&& args )
|
|
: base( in_place_init, boost::forward<Args>(args) )
|
|
{}
|
|
|
|
explicit optional ( in_place_init_t )
|
|
: base( in_place_init )
|
|
{}
|
|
|
|
template<class Args>
|
|
explicit optional ( in_place_init_if_t, bool cond, Args&& args )
|
|
: base( in_place_init_if, cond, boost::forward<Args>(args) )
|
|
{}
|
|
|
|
explicit optional ( in_place_init_if_t, bool cond )
|
|
: base( in_place_init_if, cond )
|
|
{}
|
|
#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();
|
|
}
|
|
|
|
template<class Arg>
|
|
explicit optional ( in_place_init_t, const Arg& arg )
|
|
: base( in_place_init, arg )
|
|
{}
|
|
|
|
template<class Arg>
|
|
explicit optional ( in_place_init_t, Arg& arg )
|
|
: base( in_place_init, arg )
|
|
{}
|
|
|
|
explicit optional ( in_place_init_t )
|
|
: base( in_place_init )
|
|
{}
|
|
|
|
template<class Arg>
|
|
explicit optional ( in_place_init_if_t, bool cond, const Arg& arg )
|
|
: base( in_place_init_if, cond, arg )
|
|
{}
|
|
|
|
template<class Arg>
|
|
explicit optional ( in_place_init_if_t, bool cond, Arg& arg )
|
|
: base( in_place_init_if, cond, arg )
|
|
{}
|
|
|
|
explicit optional ( in_place_init_if_t, bool cond )
|
|
: base( in_place_init_if, cond )
|
|
{}
|
|
#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 boost::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 boost::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 boost::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
|
|
|
|
|
|
#if (!defined BOOST_NO_CXX11_REF_QUALIFIERS) && (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES)
|
|
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 boost::move(get());
|
|
else
|
|
return f();
|
|
}
|
|
|
|
template <typename F>
|
|
optional<typename boost::result_of<F(reference_type)>::type> map(F f) &
|
|
{
|
|
if (this->has_value())
|
|
return f(get());
|
|
else
|
|
return none;
|
|
}
|
|
|
|
template <typename F>
|
|
optional<typename boost::result_of<F(reference_const_type)>::type> map(F f) const&
|
|
{
|
|
if (this->has_value())
|
|
return f(get());
|
|
else
|
|
return none;
|
|
}
|
|
|
|
template <typename F>
|
|
optional<typename boost::result_of<F(reference_type_of_temporary_wrapper)>::type> map(F f) &&
|
|
{
|
|
if (this->has_value())
|
|
return f(boost::move(this->get()));
|
|
else
|
|
return none;
|
|
}
|
|
|
|
template <typename F>
|
|
optional<typename optional_detail::optional_value_type<typename boost::result_of<F(reference_type)>::type>::type> flat_map(F f) &
|
|
{
|
|
if (this->has_value())
|
|
return f(get());
|
|
else
|
|
return none;
|
|
}
|
|
|
|
template <typename F>
|
|
optional<typename optional_detail::optional_value_type<typename boost::result_of<F(reference_const_type)>::type>::type> flat_map(F f) const&
|
|
{
|
|
if (this->has_value())
|
|
return f(get());
|
|
else
|
|
return none;
|
|
}
|
|
|
|
template <typename F>
|
|
optional<typename optional_detail::optional_value_type<typename boost::result_of<F(reference_type_of_temporary_wrapper)>::type>::type> flat_map(F f) &&
|
|
{
|
|
if (this->has_value())
|
|
return f(boost::move(get()));
|
|
else
|
|
return none;
|
|
}
|
|
|
|
#else
|
|
template <typename F>
|
|
value_type value_or_eval ( F f ) const
|
|
{
|
|
if (this->is_initialized())
|
|
return get();
|
|
else
|
|
return f();
|
|
}
|
|
|
|
template <typename F>
|
|
optional<typename boost::result_of<F(reference_type)>::type> map(F f)
|
|
{
|
|
if (this->has_value())
|
|
return f(get());
|
|
else
|
|
return none;
|
|
}
|
|
|
|
template <typename F>
|
|
optional<typename boost::result_of<F(reference_const_type)>::type> map(F f) const
|
|
{
|
|
if (this->has_value())
|
|
return f(get());
|
|
else
|
|
return none;
|
|
}
|
|
|
|
template <typename F>
|
|
optional<typename optional_detail::optional_value_type<typename boost::result_of<F(reference_type)>::type>::type> flat_map(F f)
|
|
{
|
|
if (this->has_value())
|
|
return f(get());
|
|
else
|
|
return none;
|
|
}
|
|
|
|
template <typename F>
|
|
optional<typename optional_detail::optional_value_type<typename boost::result_of<F(reference_const_type)>::type>::type> flat_map(F f) const
|
|
{
|
|
if (this->has_value())
|
|
return f(get());
|
|
else
|
|
return none;
|
|
}
|
|
|
|
#endif
|
|
|
|
bool has_value() const BOOST_NOEXCEPT { return this->is_initialized() ; }
|
|
|
|
bool operator!() const BOOST_NOEXCEPT { return !this->is_initialized() ; }
|
|
|
|
BOOST_EXPLICIT_OPERATOR_BOOL_NOEXCEPT()
|
|
} ;
|
|
|
|
} // namespace boost
|
|
|
|
#endif // BOOST_OPTIONAL_CONFIG_USE_OLD_IMPLEMENTATION_OF_OPTIONAL
|
|
|
|
namespace boost {
|
|
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
|
template<class T>
|
|
class optional<T&&>
|
|
{
|
|
BOOST_STATIC_ASSERT_MSG(sizeof(T) == 0, "Optional rvalue references are illegal.");
|
|
} ;
|
|
#endif
|
|
|
|
} // namespace boost
|
|
|
|
#ifndef BOOST_OPTIONAL_CONFIG_DONT_SPECIALIZE_OPTIONAL_REFS
|
|
# include <boost/optional/detail/optional_reference_spec.hpp>
|
|
#endif
|
|
|
|
namespace boost {
|
|
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
|
|
|
template<class T>
|
|
inline
|
|
optional<BOOST_DEDUCED_TYPENAME boost::decay<T>::type> make_optional ( T && v )
|
|
{
|
|
return optional<BOOST_DEDUCED_TYPENAME boost::decay<T>::type>(boost::forward<T>(v));
|
|
}
|
|
|
|
// Returns optional<T>(cond,v)
|
|
template<class T>
|
|
inline
|
|
optional<BOOST_DEDUCED_TYPENAME boost::decay<T>::type> make_optional ( bool cond, T && v )
|
|
{
|
|
return optional<BOOST_DEDUCED_TYPENAME boost::decay<T>::type>(cond,boost::forward<T>(v));
|
|
}
|
|
|
|
#else
|
|
|
|
// Returns optional<T>(v)
|
|
template<class T>
|
|
inline
|
|
optional<T> make_optional ( T const& v )
|
|
{
|
|
return optional<T>(v);
|
|
}
|
|
|
|
// Returns optional<T>(cond,v)
|
|
template<class T>
|
|
inline
|
|
optional<T> make_optional ( bool cond, T const& v )
|
|
{
|
|
return optional<T>(cond,v);
|
|
}
|
|
|
|
#endif // BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
|
|
|
// Returns a reference to the value if this is initialized, otherwise, the behaviour is UNDEFINED.
|
|
// No-throw
|
|
template<class T>
|
|
inline
|
|
BOOST_DEDUCED_TYPENAME optional<T>::reference_const_type
|
|
get ( optional<T> const& opt )
|
|
{
|
|
return opt.get() ;
|
|
}
|
|
|
|
template<class T>
|
|
inline
|
|
BOOST_DEDUCED_TYPENAME optional<T>::reference_type
|
|
get ( optional<T>& opt )
|
|
{
|
|
return opt.get() ;
|
|
}
|
|
|
|
// Returns a pointer to the value if this is initialized, otherwise, returns NULL.
|
|
// No-throw
|
|
template<class T>
|
|
inline
|
|
BOOST_DEDUCED_TYPENAME optional<T>::pointer_const_type
|
|
get ( optional<T> const* opt )
|
|
{
|
|
return opt->get_ptr() ;
|
|
}
|
|
|
|
template<class T>
|
|
inline
|
|
BOOST_DEDUCED_TYPENAME optional<T>::pointer_type
|
|
get ( optional<T>* opt )
|
|
{
|
|
return opt->get_ptr() ;
|
|
}
|
|
|
|
// Returns a reference to the value if this is initialized, otherwise, the behaviour is UNDEFINED.
|
|
// No-throw
|
|
template<class T>
|
|
inline
|
|
BOOST_DEDUCED_TYPENAME optional<T>::reference_const_type
|
|
get_optional_value_or ( optional<T> const& opt, BOOST_DEDUCED_TYPENAME optional<T>::reference_const_type v )
|
|
{
|
|
return opt.get_value_or(v) ;
|
|
}
|
|
|
|
template<class T>
|
|
inline
|
|
BOOST_DEDUCED_TYPENAME optional<T>::reference_type
|
|
get_optional_value_or ( optional<T>& opt, BOOST_DEDUCED_TYPENAME optional<T>::reference_type v )
|
|
{
|
|
return opt.get_value_or(v) ;
|
|
}
|
|
|
|
// Returns a pointer to the value if this is initialized, otherwise, returns NULL.
|
|
// No-throw
|
|
template<class T>
|
|
inline
|
|
BOOST_DEDUCED_TYPENAME optional<T>::pointer_const_type
|
|
get_pointer ( optional<T> const& opt )
|
|
{
|
|
return opt.get_ptr() ;
|
|
}
|
|
|
|
template<class T>
|
|
inline
|
|
BOOST_DEDUCED_TYPENAME optional<T>::pointer_type
|
|
get_pointer ( optional<T>& opt )
|
|
{
|
|
return opt.get_ptr() ;
|
|
}
|
|
|
|
} // namespace boost
|
|
|
|
namespace boost {
|
|
|
|
// The following declaration prevents a bug where operator safe-bool is used upon streaming optional object if you forget the IO header.
|
|
template<class CharType, class CharTrait>
|
|
std::basic_ostream<CharType, CharTrait>&
|
|
operator<<(std::basic_ostream<CharType, CharTrait>& os, optional_detail::optional_tag const&)
|
|
{
|
|
BOOST_STATIC_ASSERT_MSG(sizeof(CharType) == 0, "If you want to output boost::optional, include header <boost/optional/optional_io.hpp>");
|
|
return os;
|
|
}
|
|
|
|
} // namespace boost
|
|
|
|
#include <boost/optional/detail/optional_relops.hpp>
|
|
#include <boost/optional/detail/optional_swap.hpp>
|
|
|
|
#endif // header guard
|