1 // Copyright David Abrahams 2006. Distributed under the Boost 2 // Software License, Version 1.0. (See accompanying 3 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 4 #ifndef BOOST_CONCEPT_REQUIRES_DWA2006430_HPP 5 # define BOOST_CONCEPT_REQUIRES_DWA2006430_HPP 6 7 # include <boost/config.hpp> 8 # include <boost/concept/assert.hpp> 9 # include <boost/preprocessor/seq/for_each.hpp> 10 11 namespace boost { 12 13 // unaryfunptr_arg_type from parameter/aux_/parenthesized_type.hpp 14 15 namespace ccheck_aux { 16 17 // A metafunction that transforms void(*)(T) -> T 18 template <class UnaryFunctionPointer> 19 struct unaryfunptr_arg_type; 20 21 template <class Arg> 22 struct unaryfunptr_arg_type<void(*)(Arg)> 23 { 24 typedef Arg type; 25 }; 26 27 template <> 28 struct unaryfunptr_arg_type<void(*)(void)> 29 { 30 typedef void type; 31 }; 32 33 } // namespace ccheck_aux 34 35 // Template for use in handwritten assertions 36 template <class Model, class More> 37 struct requires_ : More 38 { 39 BOOST_CONCEPT_ASSERT((Model)); 40 }; 41 42 // Template for use by macros, where models must be wrapped in parens. 43 // This isn't in namespace detail to keep extra cruft out of resulting 44 // error messages. 45 template <class ModelFn> 46 struct _requires_ 47 { 48 enum { value = 0 }; 49 BOOST_CONCEPT_ASSERT_FN(ModelFn); 50 }; 51 52 template <int check, class Result> 53 struct Requires_ : ::boost::ccheck_aux::unaryfunptr_arg_type<Result> 54 { 55 }; 56 57 # if BOOST_WORKAROUND(BOOST_INTEL_WIN, BOOST_TESTED_AT(1010)) 58 # define BOOST_CONCEPT_REQUIRES_(r,data,t) | (::boost::_requires_<void(*)t>::value) 59 # else 60 # define BOOST_CONCEPT_REQUIRES_(r,data,t) + (::boost::_requires_<void(*)t>::value) 61 # endif 62 63 #if defined(NDEBUG) 64 65 # define BOOST_CONCEPT_REQUIRES(models, result) \ 66 typename ::boost::ccheck_aux::unaryfunptr_arg_type<void(*)result>::type 67 68 #elif BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564)) 69 70 // Same thing as below without the initial typename 71 # define BOOST_CONCEPT_REQUIRES(models, result) \ 72 ::boost::Requires_< \ 73 (0 BOOST_PP_SEQ_FOR_EACH(BOOST_CONCEPT_REQUIRES_, ~, models)), \ 74 ::boost::ccheck_aux::unaryfunptr_arg_type<void(*)result> \ 75 >::type 76 77 #else 78 79 // This just ICEs on MSVC6 :( 80 # define BOOST_CONCEPT_REQUIRES(models, result) \ 81 typename ::boost::Requires_< \ 82 (0 BOOST_PP_SEQ_FOR_EACH(BOOST_CONCEPT_REQUIRES_, ~, models)), \ 83 void(*)result \ 84 >::type 85 86 #endif 87 88 // C++0x proposed syntax changed. This supports an older usage 89 #define BOOST_CONCEPT_WHERE(models,result) BOOST_CONCEPT_REQUIRES(models,result) 90 91 } // namespace boost::concept_check 92 93 #endif // BOOST_CONCEPT_REQUIRES_DWA2006430_HPP 94