count_impl.hpp

boost库提供标准的C++ API 配合dev c++使用,功能更加强大

#ifndef BOOST_MPL_MULTISET_AUX_COUNT_IMPL_HPP_INCLUDED
#define BOOST_MPL_MULTISET_AUX_COUNT_IMPL_HPP_INCLUDED

// + file: boost/mpl/multiset/aux_/count_impl.hpp
// + last modified: 05/nov/03

// Copyright Aleksey Gurtovoy 2003
//
// 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/mpl for documentation.

#include "boost/mpl/multiset/aux_/tag.hpp"
#include "boost/mpl/count_fwd.hpp"
#include "boost/mpl/int.hpp"
#include "boost/mpl/aux_/type_wrapper.hpp"
#include "boost/mpl/aux_/static_cast.hpp"
#include "boost/mpl/aux_/config/static_constant.hpp"
#include "boost/mpl/aux_/config/workaround.hpp"
#include "boost/mpl/aux_/config/msvc.hpp"

#if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
#   include "boost/mpl/if.hpp"
#   include "boost/type_traits/is_reference.hpp"
#endif

namespace boost { namespace mpl {

#if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)

namespace aux {
template< typename S, typename U >
struct multiset_count_impl
    : int_< sizeof(S::key_count(BOOST_MPL_AUX_STATIC_CAST(U*,0))) - 1 >
{
};

template< typename S, typename U >
struct multiset_count_ref_impl
{
    typedef U (* u_)();
    typedef int_< sizeof(S::ref_key_count(BOOST_MPL_AUX_STATIC_CAST(u_,0))) - 1 > type_;
    BOOST_STATIC_CONSTANT(int, value = type_::value);
    typedef type_ type;
};
}

template<>
struct count_impl< aux::multiset_tag >
{
    template< typename Set, typename Key > struct apply
        : if_< 
              is_reference<Key>
            , aux::multiset_count_ref_impl<Set,Key>
            , aux::multiset_count_impl<Set,Key>
            >::type
    {
    };
};

#else

template<>
struct count_impl< aux::multiset_tag >
{
    template< typename Set, typename Key > struct apply
    {
        enum { msvc71_wknd_ = sizeof(Set::key_count(BOOST_MPL_AUX_STATIC_CAST(aux::type_wrapper<Key>*,0))) - 1 };
        typedef int_< msvc71_wknd_ > type;
        BOOST_STATIC_CONSTANT(int, value = msvc71_wknd_);
    };
};

#endif // BOOST_WORKAROUND(BOOST_MSVC, <= 1300)

}} // namespace boost::mpl

#endif // BOOST_MPL_MULTISET_AUX_COUNT_IMPL_HPP_INCLUDED