mirror of
https://github.com/boostorg/utility.git
synced 2025-05-09 15:04:00 +00:00
121 lines
2.6 KiB
C++
121 lines
2.6 KiB
C++
#ifndef BOOST_REF_HPP_INCLUDED
|
|
#define BOOST_REF_HPP_INCLUDED
|
|
|
|
// MS compatible compilers support #pragma once
|
|
|
|
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
|
|
# pragma once
|
|
#endif
|
|
|
|
#include <boost/config.hpp>
|
|
#include <boost/utility/addressof.hpp>
|
|
#include <boost/mpl/bool.hpp>
|
|
#include <boost/detail/workaround.hpp>
|
|
|
|
//
|
|
// ref.hpp - ref/cref, useful helper functions
|
|
//
|
|
// Copyright (C) 1999, 2000 Jaakko Jarvi (jaakko.jarvi@cs.utu.fi)
|
|
// Copyright (C) 2001, 2002 Peter Dimov
|
|
// Copyright (C) 2002 David Abrahams
|
|
//
|
|
// Distributed under the Boost Software License, Version 1.0. (See
|
|
// accompanying file LICENSE_1_0.txt or copy at
|
|
// http://www.boost.org/LICENSE_1_0.txt)
|
|
//
|
|
// See http://www.boost.org/libs/bind/ref.html for documentation.
|
|
//
|
|
|
|
namespace boost
|
|
{
|
|
|
|
template<class T> class reference_wrapper
|
|
{
|
|
public:
|
|
typedef T type;
|
|
|
|
BOOST_FORCEINLINE explicit reference_wrapper(T& t): t_(boost::addressof(t)) {}
|
|
|
|
BOOST_FORCEINLINE operator T& () const { return *t_; }
|
|
|
|
BOOST_FORCEINLINE T& get() const { return *t_; }
|
|
|
|
BOOST_FORCEINLINE T* get_pointer() const { return t_; }
|
|
|
|
private:
|
|
|
|
T* t_;
|
|
};
|
|
|
|
# if defined( __BORLANDC__ ) && BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT(0x581) )
|
|
# define BOOST_REF_CONST
|
|
# else
|
|
# define BOOST_REF_CONST const
|
|
# endif
|
|
|
|
template<class T> BOOST_FORCEINLINE reference_wrapper<T> BOOST_REF_CONST ref(T & t)
|
|
{
|
|
return reference_wrapper<T>(t);
|
|
}
|
|
|
|
template<class T> BOOST_FORCEINLINE reference_wrapper<T const> BOOST_REF_CONST cref(T const & t)
|
|
{
|
|
return reference_wrapper<T const>(t);
|
|
}
|
|
|
|
# undef BOOST_REF_CONST
|
|
|
|
|
|
template<typename T>
|
|
class is_reference_wrapper
|
|
: public mpl::false_
|
|
{
|
|
};
|
|
|
|
template<typename T>
|
|
class unwrap_reference
|
|
{
|
|
public:
|
|
typedef T type;
|
|
};
|
|
|
|
# define AUX_REFERENCE_WRAPPER_METAFUNCTIONS_DEF(X) \
|
|
template<typename T> \
|
|
class is_reference_wrapper< X > \
|
|
: public mpl::true_ \
|
|
{ \
|
|
}; \
|
|
\
|
|
template<typename T> \
|
|
class unwrap_reference< X > \
|
|
{ \
|
|
public: \
|
|
typedef T type; \
|
|
}; \
|
|
/**/
|
|
|
|
AUX_REFERENCE_WRAPPER_METAFUNCTIONS_DEF(reference_wrapper<T>)
|
|
#if !defined(BOOST_NO_CV_SPECIALIZATIONS)
|
|
AUX_REFERENCE_WRAPPER_METAFUNCTIONS_DEF(reference_wrapper<T> const)
|
|
AUX_REFERENCE_WRAPPER_METAFUNCTIONS_DEF(reference_wrapper<T> volatile)
|
|
AUX_REFERENCE_WRAPPER_METAFUNCTIONS_DEF(reference_wrapper<T> const volatile)
|
|
#endif
|
|
|
|
# undef AUX_REFERENCE_WRAPPER_METAFUNCTIONS_DEF
|
|
|
|
|
|
template <class T> BOOST_FORCEINLINE typename unwrap_reference<T>::type&
|
|
unwrap_ref(T& t)
|
|
{
|
|
return t;
|
|
}
|
|
|
|
template<class T> BOOST_FORCEINLINE T* get_pointer( reference_wrapper<T> const & r )
|
|
{
|
|
return r.get_pointer();
|
|
}
|
|
|
|
} // namespace boost
|
|
|
|
#endif // #ifndef BOOST_REF_HPP_INCLUDED
|