forked from boostorg/detail
146 lines
3.3 KiB
C++
146 lines
3.3 KiB
C++
//-----------------------------------------------------------------------------
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// boost detail/reference_content.hpp header file
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// See http://www.boost.org for updates, documentation, and revision history.
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//-----------------------------------------------------------------------------
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//
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// Copyright (c) 2003
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// Eric Friedman
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//
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// Permission to use, copy, modify, distribute and sell this software
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// and its documentation for any purpose is hereby granted without fee,
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// provided that the above copyright notice appears in all copies and
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// that both the copyright notice and this permission notice appear in
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// supporting documentation. No representations are made about the
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// suitability of this software for any purpose. It is provided "as is"
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// without express or implied warranty.
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#ifndef BOOST_DETAIL_REFERENCE_CONTENT_HPP
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#define BOOST_DETAIL_REFERENCE_CONTENT_HPP
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#include "boost/config.hpp"
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#if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
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# include "boost/mpl/bool.hpp"
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# include "boost/type_traits/has_nothrow_copy.hpp"
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#else
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# include "boost/mpl/if.hpp"
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# include "boost/type_traits/is_reference.hpp"
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#endif
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#include "boost/mpl/void.hpp"
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namespace boost {
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namespace detail {
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///////////////////////////////////////////////////////////////////////////////
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// (detail) class template reference_content
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//
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// Non-Assignable wrapper for references.
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//
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template <typename RefT>
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class reference_content
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{
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private: // representation
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RefT content_;
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public: // structors
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~reference_content()
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{
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}
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reference_content(RefT r)
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: content_( r )
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{
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}
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reference_content(const reference_content& operand)
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: content_( operand.content_ )
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{
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}
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private: // non-Assignable
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reference_content& operator=(const reference_content&);
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public: // queries
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RefT get() const
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{
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return content_;
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}
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};
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///////////////////////////////////////////////////////////////////////////////
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// (detail) metafunction make_reference_content
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//
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// Wraps with reference_content if specified type is reference.
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//
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template <typename T = mpl::void_> struct make_reference_content;
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#if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
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template <typename T>
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struct make_reference_content
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{
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typedef T type;
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};
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template <typename T>
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struct make_reference_content< T& >
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{
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typedef reference_content<T&> type;
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};
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#else // defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
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template <typename T>
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struct make_reference_content
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: mpl::if_<
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is_reference<T>
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, reference_content<T>
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, T
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>
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{
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};
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#endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION workaround
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template <>
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struct make_reference_content< mpl::void_ >
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{
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template <typename T>
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struct apply
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: make_reference_content<T>
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{
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};
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typedef mpl::void_ type;
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};
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} // namespace detail
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///////////////////////////////////////////////////////////////////////////////
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// reference_content<T&> type traits specializations
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//
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#if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
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template <typename T>
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struct has_nothrow_copy<
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::boost::detail::reference_content< T& >
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>
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: mpl::true_
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{
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};
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#endif // !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
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} // namespace boost
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#endif // BOOST_DETAIL_REFERENCE_CONTENT_HPP
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