sl@0: #ifndef BOOST_REF_HPP_INCLUDED
sl@0: #define BOOST_REF_HPP_INCLUDED
sl@0: 
sl@0: // MS compatible compilers support #pragma once
sl@0: 
sl@0: #if defined(_MSC_VER) && (_MSC_VER >= 1020)
sl@0: # pragma once
sl@0: #endif
sl@0: 
sl@0: #include <boost/config.hpp>
sl@0: #include <boost/utility/addressof.hpp>
sl@0: #include <boost/mpl/bool.hpp>
sl@0: #include <boost/detail/workaround.hpp>
sl@0: 
sl@0: //
sl@0: //  ref.hpp - ref/cref, useful helper functions
sl@0: //
sl@0: //  Copyright (C) 1999, 2000 Jaakko Järvi (jaakko.jarvi@cs.utu.fi)
sl@0: //  Copyright (C) 2001, 2002 Peter Dimov
sl@0: //  Copyright (C) 2002 David Abrahams
sl@0: //
sl@0: // Distributed under the Boost Software License, Version 1.0. (See
sl@0: // accompanying file LICENSE_1_0.txt or copy at
sl@0: // http://www.boost.org/LICENSE_1_0.txt)
sl@0: //
sl@0: //  See http://www.boost.org/libs/bind/ref.html for documentation.
sl@0: //
sl@0: 
sl@0: namespace boost
sl@0: {
sl@0: 
sl@0: template<class T> class reference_wrapper
sl@0: { 
sl@0: public:
sl@0:     typedef T type;
sl@0: 
sl@0: #if defined( BOOST_MSVC ) && BOOST_WORKAROUND( BOOST_MSVC, < 1300 )
sl@0: 
sl@0:     explicit reference_wrapper(T& t): t_(&t) {}
sl@0: 
sl@0: #else
sl@0: 
sl@0:     explicit reference_wrapper(T& t): t_(boost::addressof(t)) {}
sl@0: 
sl@0: #endif
sl@0: 
sl@0:     operator T& () const { return *t_; }
sl@0: 
sl@0:     T& get() const { return *t_; }
sl@0: 
sl@0:     T* get_pointer() const { return t_; }
sl@0: 
sl@0: private:
sl@0: 
sl@0:     T* t_;
sl@0: };
sl@0: 
sl@0: # if defined( __BORLANDC__ ) && BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT(0x581) )
sl@0: #  define BOOST_REF_CONST
sl@0: # else
sl@0: #  define BOOST_REF_CONST const
sl@0: # endif
sl@0: 
sl@0: template<class T> inline reference_wrapper<T> BOOST_REF_CONST ref(T & t)
sl@0: { 
sl@0:     return reference_wrapper<T>(t);
sl@0: }
sl@0: 
sl@0: template<class T> inline reference_wrapper<T const> BOOST_REF_CONST cref(T const & t)
sl@0: {
sl@0:     return reference_wrapper<T const>(t);
sl@0: }
sl@0: 
sl@0: # undef BOOST_REF_CONST
sl@0: 
sl@0: # ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
sl@0: 
sl@0: template<typename T>
sl@0: class is_reference_wrapper
sl@0:     : public mpl::false_
sl@0: {
sl@0: };
sl@0: 
sl@0: template<typename T>
sl@0: class unwrap_reference
sl@0: {
sl@0:  public:
sl@0:     typedef T type;
sl@0: };
sl@0: 
sl@0: #  define AUX_REFERENCE_WRAPPER_METAFUNCTIONS_DEF(X) \
sl@0: template<typename T> \
sl@0: class is_reference_wrapper< X > \
sl@0:     : public mpl::true_ \
sl@0: { \
sl@0: }; \
sl@0: \
sl@0: template<typename T> \
sl@0: class unwrap_reference< X > \
sl@0: { \
sl@0:  public: \
sl@0:     typedef T type; \
sl@0: }; \
sl@0: /**/
sl@0: 
sl@0: AUX_REFERENCE_WRAPPER_METAFUNCTIONS_DEF(reference_wrapper<T>)
sl@0: #if !defined(BOOST_NO_CV_SPECIALIZATIONS)
sl@0: AUX_REFERENCE_WRAPPER_METAFUNCTIONS_DEF(reference_wrapper<T> const)
sl@0: AUX_REFERENCE_WRAPPER_METAFUNCTIONS_DEF(reference_wrapper<T> volatile)
sl@0: AUX_REFERENCE_WRAPPER_METAFUNCTIONS_DEF(reference_wrapper<T> const volatile)
sl@0: #endif
sl@0: 
sl@0: #  undef AUX_REFERENCE_WRAPPER_METAFUNCTIONS_DEF
sl@0: 
sl@0: # else // no partial specialization
sl@0: 
sl@0: } // namespace boost
sl@0: 
sl@0: #include <boost/type.hpp>
sl@0: 
sl@0: namespace boost
sl@0: {
sl@0: 
sl@0: namespace detail
sl@0: {
sl@0:   typedef char (&yes_reference_wrapper_t)[1];
sl@0:   typedef char (&no_reference_wrapper_t)[2];
sl@0:       
sl@0:   no_reference_wrapper_t is_reference_wrapper_test(...);
sl@0: 
sl@0:   template<typename T>
sl@0:   yes_reference_wrapper_t is_reference_wrapper_test(type< reference_wrapper<T> >);
sl@0: 
sl@0:   template<bool wrapped>
sl@0:   struct reference_unwrapper
sl@0:   {
sl@0:       template <class T>
sl@0:       struct apply
sl@0:       {
sl@0:           typedef T type;
sl@0:       };
sl@0:   };
sl@0: 
sl@0:   template<>
sl@0:   struct reference_unwrapper<true>
sl@0:   {
sl@0:       template <class T>
sl@0:       struct apply
sl@0:       {
sl@0:           typedef typename T::type type;
sl@0:       };
sl@0:   };
sl@0: }
sl@0: 
sl@0: template<typename T>
sl@0: class is_reference_wrapper
sl@0: {
sl@0:  public:
sl@0:     BOOST_STATIC_CONSTANT(
sl@0:         bool, value = (
sl@0:              sizeof(detail::is_reference_wrapper_test(type<T>()))
sl@0:             == sizeof(detail::yes_reference_wrapper_t)));
sl@0:     
sl@0:     typedef ::boost::mpl::bool_<value> type;
sl@0: };
sl@0: 
sl@0: template <typename T>
sl@0: class unwrap_reference
sl@0:     : public detail::reference_unwrapper<
sl@0:         is_reference_wrapper<T>::value
sl@0:       >::template apply<T>
sl@0: {};
sl@0: 
sl@0: # endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
sl@0: 
sl@0: } // namespace boost
sl@0: 
sl@0: #endif // #ifndef BOOST_REF_HPP_INCLUDED