// (C) Copyright Dave Abrahams, Steve Cleary, Beman Dawes, | |
// Howard Hinnant and John Maddock 2000. | |
// (C) Copyright Mat Marcus, Jesse Jones and Adobe Systems Inc 2001 | |
// Use, modification and distribution are subject to 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/type_traits for most recent version including documentation. | |
// Fixed is_pointer, is_reference, is_const, is_volatile, is_same, | |
// is_member_pointer based on the Simulated Partial Specialization work | |
// of Mat Marcus and Jesse Jones. See http://opensource.adobe.com or | |
// http://groups.yahoo.com/group/boost/message/5441 | |
// Some workarounds in here use ideas suggested from "Generic<Programming>: | |
// Mappings between Types and Values" | |
// by Andrei Alexandrescu (see http://www.cuj.com/experts/1810/alexandr.html). | |
#ifndef BOOST_TT_IS_SAME_HPP_INCLUDED | |
#define BOOST_TT_IS_SAME_HPP_INCLUDED | |
#include <boost/type_traits/config.hpp> | |
#ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION | |
#include <boost/type_traits/detail/yes_no_type.hpp> | |
#include <boost/type_traits/detail/ice_and.hpp> | |
#include <boost/type_traits/is_reference.hpp> | |
#endif | |
// should be the last #include | |
#include <boost/type_traits/detail/bool_trait_def.hpp> | |
namespace boost { | |
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION | |
BOOST_TT_AUX_BOOL_TRAIT_DEF2(is_same,T,U,false) | |
BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC2_1(typename T,is_same,T,T,true) | |
#if BOOST_WORKAROUND(__BORLANDC__, < 0x600) | |
// without this, Borland's compiler gives the wrong answer for | |
// references to arrays: | |
BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC2_1(typename T,is_same,T&,T&,true) | |
#endif | |
#else // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION | |
namespace detail { | |
#ifdef BOOST_MSVC | |
// the following VC6 specific implementation is *NOT* legal | |
// C++, but has the advantage that it works for incomplete | |
// types. | |
template< typename T1 > | |
struct is_same_part_1 | |
{ | |
template<typename T2> struct part_2 { enum { value = false }; }; | |
template<> struct part_2<T1> { enum { value = true }; }; | |
}; | |
template< typename T1, typename T2 > | |
struct is_same_impl | |
{ | |
enum { value = boost::detail::is_same_part_1<T1>::template part_2<T2>::value }; | |
}; | |
#else // generic "no-partial-specialization" version | |
template <typename T> | |
::boost::type_traits::yes_type | |
BOOST_TT_DECL is_same_tester(T*, T*); | |
::boost::type_traits::no_type | |
BOOST_TT_DECL is_same_tester(...); | |
template <typename T, typename U> | |
struct is_same_impl | |
{ | |
static T t; | |
static U u; | |
BOOST_STATIC_CONSTANT(bool, value = | |
(::boost::type_traits::ice_and< | |
(sizeof(type_traits::yes_type) == sizeof(boost::detail::is_same_tester(&t,&u))), | |
(::boost::is_reference<T>::value == ::boost::is_reference<U>::value), | |
(sizeof(T) == sizeof(U)) | |
>::value)); | |
}; | |
#endif // BOOST_MSVC | |
} // namespace detail | |
BOOST_TT_AUX_BOOL_TRAIT_DEF2(is_same,T,U,(::boost::detail::is_same_impl<T,U>::value)) | |
#endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION | |
} // namespace boost | |
#include <boost/type_traits/detail/bool_trait_undef.hpp> | |
#endif // BOOST_TT_IS_SAME_HPP_INCLUDED | |