// Copyright David Abrahams 2006. 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)

#ifndef BOOST_CONCEPT_DETAIL_GENERAL_DWA2006429_HPP

# define BOOST_CONCEPT_DETAIL_GENERAL_DWA2006429_HPP

# include <boost/preprocessor/cat.hpp>

# ifdef BOOST_OLD_CONCEPT_SUPPORT

#  include <boost/concept/detail/has_constraints.hpp>

#  include <boost/mpl/if.hpp>

# endif

// This implementation works on Comeau and GCC, all the way back to

// 2.95

namespace boost { namespace concept {

template <class ModelFn>

struct requirement_;

namespace detail

{

  template <void(*)()> struct instantiate {};

}

template <class Model>

struct requirement

{

    static void failed() { ((Model*)0)->~Model(); }

};

# ifdef BOOST_OLD_CONCEPT_SUPPORT

template <class Model>

struct constraint

{

    static void failed() { ((Model*)0)->constraints(); }

};

template <class Model>

struct requirement_<void(*)(Model)>

  : mpl::if_<

        concept::not_satisfied<Model>

      , constraint<Model>

      , requirement<Model>

    >::type

{};

# else

// For GCC-2.x, these can't have exactly the same name

template <class Model>

struct requirement_<void(*)(Model)>

  : requirement<Model>

{};

# endif

#  define BOOST_CONCEPT_ASSERT_FN( ModelFnPtr )             \

    typedef ::boost::concept::detail::instantiate<          \

    &::boost::concept::requirement_<ModelFnPtr>::failed>    \

      BOOST_PP_CAT(boost_concept_check,__LINE__)

}}

#endif // BOOST_CONCEPT_DETAIL_GENERAL_DWA2006429_HPP