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152 lines
3.2 KiB
C++
152 lines
3.2 KiB
C++
#ifndef BOOST_REF_HPP_INCLUDED
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#define BOOST_REF_HPP_INCLUDED
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// MS compatible compilers support #pragma once
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#if defined(_MSC_VER) && (_MSC_VER >= 1020)
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# pragma once
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#endif
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#include <boost/config.hpp>
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#include <boost/utility/addressof.hpp>
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#include <boost/detail/workaround.hpp>
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//
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// ref.hpp - ref/cref, useful helper functions
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//
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// Copyright (C) 1999, 2000 Jaakko Jarvi (jaakko.jarvi@cs.utu.fi)
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// Copyright (C) 2001, 2002 Peter Dimov
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// Copyright (C) 2002 David Abrahams
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//
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// Distributed under the Boost Software License, Version 1.0. (See
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// 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/bind/ref.html for documentation.
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//
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namespace boost
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{
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// reference_wrapper
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template<class T> class reference_wrapper
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{
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public:
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typedef T type;
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BOOST_FORCEINLINE explicit reference_wrapper(T& t): t_(boost::addressof(t)) {}
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BOOST_FORCEINLINE operator T& () const { return *t_; }
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BOOST_FORCEINLINE T& get() const { return *t_; }
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BOOST_FORCEINLINE T* get_pointer() const { return t_; }
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private:
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T* t_;
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};
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// ref
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# if defined( __BORLANDC__ ) && BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT(0x581) )
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# define BOOST_REF_CONST
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# else
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# define BOOST_REF_CONST const
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# endif
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template<class T> BOOST_FORCEINLINE reference_wrapper<T> BOOST_REF_CONST ref( T & t )
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{
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return reference_wrapper<T>(t);
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}
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// cref
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template<class T> BOOST_FORCEINLINE reference_wrapper<T const> BOOST_REF_CONST cref( T const & t )
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{
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return reference_wrapper<T const>(t);
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}
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# undef BOOST_REF_CONST
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// is_reference_wrapper
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template<typename T> struct is_reference_wrapper
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{
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BOOST_STATIC_CONSTANT( bool, value = false );
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};
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template<typename T> struct is_reference_wrapper< reference_wrapper<T> >
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{
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BOOST_STATIC_CONSTANT( bool, value = true );
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};
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#if !defined(BOOST_NO_CV_SPECIALIZATIONS)
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template<typename T> struct is_reference_wrapper< reference_wrapper<T> const >
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{
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BOOST_STATIC_CONSTANT( bool, value = true );
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};
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template<typename T> struct is_reference_wrapper< reference_wrapper<T> volatile >
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{
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BOOST_STATIC_CONSTANT( bool, value = true );
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};
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template<typename T> struct is_reference_wrapper< reference_wrapper<T> const volatile >
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{
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BOOST_STATIC_CONSTANT( bool, value = true );
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};
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#endif // !defined(BOOST_NO_CV_SPECIALIZATIONS)
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// unwrap_reference
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template<typename T> struct unwrap_reference
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{
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typedef T type;
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};
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template<typename T> struct unwrap_reference< reference_wrapper<T> >
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{
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typedef T type;
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};
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#if !defined(BOOST_NO_CV_SPECIALIZATIONS)
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template<typename T> struct unwrap_reference< reference_wrapper<T> const >
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{
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typedef T type;
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};
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template<typename T> struct unwrap_reference< reference_wrapper<T> volatile >
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{
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typedef T type;
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};
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template<typename T> struct unwrap_reference< reference_wrapper<T> const volatile >
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{
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typedef T type;
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};
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#endif // !defined(BOOST_NO_CV_SPECIALIZATIONS)
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// unwrap_ref
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template<class T> BOOST_FORCEINLINE typename unwrap_reference<T>::type& unwrap_ref( T & t )
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{
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return t;
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}
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// get_pointer
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template<class T> BOOST_FORCEINLINE T* get_pointer( reference_wrapper<T> const & r )
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{
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return r.get_pointer();
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}
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} // namespace boost
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#endif // #ifndef BOOST_REF_HPP_INCLUDED
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