78 lines
2.5 KiB
C++
78 lines
2.5 KiB
C++
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//////////////////////////////////////////////////////////////////////////////
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//
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// (C) Copyright Ion Gaztanaga 2009-2012.
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// Distributed under the Boost Software License, Version 1.0.
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// (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/move for documentation.
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//
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//////////////////////////////////////////////////////////////////////////////
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//! \file
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#ifndef BOOST_MOVE_TRAITS_HPP
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#define BOOST_MOVE_TRAITS_HPP
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#ifndef BOOST_CONFIG_HPP
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# include <boost/config.hpp>
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#endif
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#
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#if defined(BOOST_HAS_PRAGMA_ONCE)
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# pragma once
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#endif
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#include <boost/move/detail/config_begin.hpp>
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#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
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#include <boost/move/core.hpp>
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#endif
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#include <boost/move/detail/meta_utils.hpp>
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#include <boost/move/detail/type_traits.hpp>
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namespace boost {
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//! If this trait yields to true
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//! (<i>has_trivial_destructor_after_move <T>::value == true</i>)
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//! means that if T is used as argument of a move construction/assignment,
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//! there is no need to call T's destructor.
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//! This optimization tipically is used to improve containers' performance.
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//!
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//! By default this trait is true if the type has trivial destructor,
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//! every class should specialize this trait if it wants to improve performance
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//! when inserted in containers.
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template <class T>
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struct has_trivial_destructor_after_move
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: ::boost::move_detail::is_trivially_destructible<T>
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{};
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//! By default this traits returns
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//! <pre>boost::is_nothrow_move_constructible<T>::value && boost::is_nothrow_move_assignable<T>::value </pre>.
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//! Classes with non-throwing move constructor
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//! and assignment can specialize this trait to obtain some performance improvements.
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template <class T>
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struct has_nothrow_move
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{
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static const bool value = boost::move_detail::is_nothrow_move_constructible<T>::value &&
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boost::move_detail::is_nothrow_move_assignable<T>::value;
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};
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namespace move_detail {
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template <class T>
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struct is_nothrow_move_constructible_or_uncopyable
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{
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//The standard requires is_nothrow_move_constructible for move_if_noexcept
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//but a user (usually in C++03) might specialize has_nothrow_move which includes it
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static const bool value = is_nothrow_move_constructible<T>::value ||
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has_nothrow_move<T>::value ||
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!is_copy_constructible<T>::value;
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};
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} //move_detail {
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} //namespace boost {
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#include <boost/move/detail/config_end.hpp>
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#endif //#ifndef BOOST_MOVE_TRAITS_HPP
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