[857] | 1 | // (C) Copyright Jonathan Turkanis 2003.
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| 2 | // Distributed under the Boost Software License, Version 1.0. (See accompanying
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| 3 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
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| 4 |
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| 5 | // See http://www.boost.org/libs/iostreams for documentation.
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| 6 |
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| 7 | #ifndef BOOST_IOSTREAMS_DETAIL_BOOL_TRAIT_DEF_HPP_INCLUDED
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| 8 | #define BOOST_IOSTREAMS_DETAIL_BOOL_TRAIT_DEF_HPP_INCLUDED
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| 9 |
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| 10 | #include <boost/config.hpp> // BOOST_STATIC_CONSTANT.
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| 11 | #include <boost/iostreams/detail/template_params.hpp>
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| 12 | #include <boost/mpl/aux_/lambda_support.hpp>
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| 13 | #include <boost/mpl/bool.hpp>
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| 14 | #include <boost/preprocessor/cat.hpp>
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| 15 | #include <boost/preprocessor/repetition/enum_params.hpp>
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| 16 | #include <boost/type_traits/detail/yes_no_type.hpp>
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| 17 |
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| 18 | //
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| 19 | // Macro name: BOOST_IOSTREAMS_BOOL_TRAIT_DEF
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| 20 | // Description: Used to generate the traits classes is_istream, is_ostream,
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| 21 | // etc.
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| 22 | //
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| 23 | #if BOOST_WORKAROUND(__BORLANDC__, <= 0x564)
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| 24 | # define BOOST_IOSTREAMS_TRAIT_NAMESPACE(trait)
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| 25 | #else
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| 26 | # define BOOST_IOSTREAMS_TRAIT_NAMESPACE(trait) BOOST_PP_CAT(trait, _impl_)::
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| 27 | #endif
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| 28 | #define BOOST_IOSTREAMS_BOOL_TRAIT_DEF(trait, type, arity) \
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| 29 | namespace BOOST_PP_CAT(trait, _impl_) { \
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| 30 | BOOST_IOSTREAMS_TEMPLATE_PARAMS(arity, T) \
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| 31 | type_traits::yes_type helper \
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| 32 | (const volatile type BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T)*); \
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| 33 | type_traits::no_type helper(...); \
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| 34 | template<typename T> \
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| 35 | struct impl { \
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| 36 | BOOST_STATIC_CONSTANT(bool, value = \
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| 37 | (sizeof(BOOST_IOSTREAMS_TRAIT_NAMESPACE(trait) \
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| 38 | helper(static_cast<T*>(0))) == \
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| 39 | sizeof(type_traits::yes_type))); \
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| 40 | }; \
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| 41 | } \
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| 42 | template<typename T> \
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| 43 | struct trait \
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| 44 | : mpl::bool_<BOOST_PP_CAT(trait, _impl_)::impl<T>::value> \
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| 45 | { BOOST_MPL_AUX_LAMBDA_SUPPORT(1, trait, (T)) }; \
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| 46 | /**/
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| 47 |
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| 48 | #endif // #ifndef BOOST_IOSTREAMS_DETAIL_BOOL_TRAIT_DEF_HPP_INCLUDED
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