//  (C) Copyright John Maddock 2015.
//  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)

#ifndef BOOST_TYPE_TRAITS_INTEGRAL_CONSTANT_HPP
#define BOOST_TYPE_TRAITS_INTEGRAL_CONSTANT_HPP

#include <boost/config.hpp>
#include <boost/detail/workaround.hpp>

#if (BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1400)) \
   || BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x610)) \
   || BOOST_WORKAROUND(__DMC__, BOOST_TESTED_AT(0x840)) \
   || BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3202)) \
   || BOOST_WORKAROUND(BOOST_INTEL_CXX_VERSION, BOOST_TESTED_AT(810)) )\
   || defined(BOOST_MPL_CFG_NO_ADL_BARRIER_NAMESPACE)

namespace boost {
namespace mpl {
template <bool B> struct bool_;
template <class I, I val> struct integral_c;
struct integral_c_tag;
}
}

#else

namespace mpl_ {

template <bool B> struct bool_;
template <class I, I val> struct integral_c;
struct integral_c_tag;
}

namespace boost {
namespace mpl {
using ::mpl_::bool_;
using ::mpl_::integral_c;
using ::mpl_::integral_c_tag;
}
}

#endif

namespace boost {

template <class T, T val>
struct integral_constant
{
    typedef mpl::integral_c_tag tag;
    typedef T value_type;
    typedef integral_constant<T, val> type;
    static const T value = val;

    operator const mpl::integral_c<T, val>& ()const
    {
        static const char data[sizeof(long)] = { 0 };
        static const void* pdata = data;
        return *(reinterpret_cast<const mpl::integral_c<T, val>*>(pdata));
    }
    BOOST_CONSTEXPR
    operator T()const
    {
        return val;
    }
};

template <class T, T val>
T const integral_constant<T, val>::value;

template <bool val>
struct integral_constant<bool, val>
{
    typedef mpl::integral_c_tag tag;
    typedef bool value_type;
    typedef integral_constant<bool, val> type;
    static const bool value = val;

    operator const mpl::bool_<val>& ()const
    {
        static const char data[sizeof(long)] = { 0 };
        static const void* pdata = data;
        return *(reinterpret_cast<const mpl::bool_<val>*>(pdata));
    }
    BOOST_CONSTEXPR
    operator bool()const
    {
        return val;
    }
};

template <bool val>
bool const integral_constant<bool, val>::value;

typedef integral_constant<bool, true> true_type;
typedef integral_constant<bool, false> false_type;

}

#endif
