// (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 |