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// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
// (C) Copyright 2003-2007 Jonathan Turkanis
// 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.)
// See http://www.boost.org/libs/iostreams for documentation.
#ifndef BOOST_IOSTREAMS_DETAIL_BOOL_TRAIT_DEF_HPP_INCLUDED
#define BOOST_IOSTREAMS_DETAIL_BOOL_TRAIT_DEF_HPP_INCLUDED
#include <boost/config.hpp> // BOOST_STATIC_CONSTANT.
#include <boost/iostreams/detail/template_params.hpp>
#include <boost/mpl/aux_/lambda_support.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/preprocessor/cat.hpp>
#include <boost/preprocessor/repetition/enum_params.hpp>
#include <boost/type_traits/detail/yes_no_type.hpp>
//
// Macro name: BOOST_IOSTREAMS_BOOL_TRAIT_DEF
// Description: Used to generate the traits classes is_istream, is_ostream,
// etc.
//
#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x582))
# define BOOST_IOSTREAMS_TRAIT_NAMESPACE(trait)
#else
# define BOOST_IOSTREAMS_TRAIT_NAMESPACE(trait) BOOST_PP_CAT(trait, _impl_)::
#endif
#define BOOST_IOSTREAMS_BOOL_TRAIT_DEF(trait, type, arity) \
namespace BOOST_PP_CAT(trait, _impl_) { \
BOOST_IOSTREAMS_TEMPLATE_PARAMS(arity, T) \
type_traits::yes_type helper \
(const volatile type BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T)*); \
type_traits::no_type helper(...); \
template<typename T> \
struct impl { \
BOOST_STATIC_CONSTANT(bool, value = \
(sizeof(BOOST_IOSTREAMS_TRAIT_NAMESPACE(trait) \
helper(static_cast<T*>(0))) == \
sizeof(type_traits::yes_type))); \
}; \
} \
template<typename T> \
struct trait \
: mpl::bool_<BOOST_PP_CAT(trait, _impl_)::impl<T>::value> \
{ BOOST_MPL_AUX_LAMBDA_SUPPORT(1, trait, (T)) }; \
/**/
#endif // #ifndef BOOST_IOSTREAMS_DETAIL_BOOL_TRAIT_DEF_HPP_INCLUDED