| 1 | // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com) |
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| 2 | // (C) Copyright 2003-2007 Jonathan Turkanis |
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| 3 | // Distributed under the Boost Software License, Version 1.0. (See accompanying |
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| 4 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.) |
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| 5 | |
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| 6 | // See http://www.boost.org/libs/iostreams for documentation. |
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| 7 | |
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| 8 | #ifndef BOOST_IOSTREAMS_DETAIL_BOOL_TRAIT_DEF_HPP_INCLUDED |
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| 9 | #define BOOST_IOSTREAMS_DETAIL_BOOL_TRAIT_DEF_HPP_INCLUDED |
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| 10 | |
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| 11 | #include <boost/config.hpp> // BOOST_STATIC_CONSTANT. |
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| 12 | #include <boost/iostreams/detail/template_params.hpp> |
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| 13 | #include <boost/mpl/aux_/lambda_support.hpp> |
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| 14 | #include <boost/mpl/bool.hpp> |
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| 15 | #include <boost/preprocessor/cat.hpp> |
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| 16 | #include <boost/preprocessor/repetition/enum_params.hpp> |
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| 17 | #include <boost/type_traits/detail/yes_no_type.hpp> |
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| 18 | |
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| 19 | // |
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| 20 | // Macro name: BOOST_IOSTREAMS_BOOL_TRAIT_DEF |
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| 21 | // Description: Used to generate the traits classes is_istream, is_ostream, |
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| 22 | // etc. |
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| 23 | // |
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| 24 | #if BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x582)) |
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| 25 | # define BOOST_IOSTREAMS_TRAIT_NAMESPACE(trait) |
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| 26 | #else |
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| 27 | # define BOOST_IOSTREAMS_TRAIT_NAMESPACE(trait) BOOST_PP_CAT(trait, _impl_):: |
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| 28 | #endif |
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| 29 | #define BOOST_IOSTREAMS_BOOL_TRAIT_DEF(trait, type, arity) \ |
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| 30 | namespace BOOST_PP_CAT(trait, _impl_) { \ |
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| 31 | BOOST_IOSTREAMS_TEMPLATE_PARAMS(arity, T) \ |
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| 32 | type_traits::yes_type helper \ |
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| 33 | (const volatile type BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T)*); \ |
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| 34 | type_traits::no_type helper(...); \ |
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| 35 | template<typename T> \ |
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| 36 | struct impl { \ |
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| 37 | BOOST_STATIC_CONSTANT(bool, value = \ |
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| 38 | (sizeof(BOOST_IOSTREAMS_TRAIT_NAMESPACE(trait) \ |
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| 39 | helper(static_cast<T*>(0))) == \ |
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| 40 | sizeof(type_traits::yes_type))); \ |
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| 41 | }; \ |
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| 42 | } \ |
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| 43 | template<typename T> \ |
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| 44 | struct trait \ |
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| 45 | : mpl::bool_<BOOST_PP_CAT(trait, _impl_)::impl<T>::value> \ |
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| 46 | { BOOST_MPL_AUX_LAMBDA_SUPPORT(1, trait, (T)) }; \ |
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| 47 | /**/ |
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| 48 | |
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| 49 | #endif // #ifndef BOOST_IOSTREAMS_DETAIL_BOOL_TRAIT_DEF_HPP_INCLUDED |
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| 50 | |
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