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_DETAIL_GENERAL_DWA2006429_HPP
5 # define BOOST_CONCEPT_DETAIL_GENERAL_DWA2006429_HPP
6 
7 # include <boost/config.hpp>
8 # include <boost/preprocessor/cat.hpp>
9 # include <boost/concept/detail/backward_compatibility.hpp>
10 
11 # ifdef BOOST_OLD_CONCEPT_SUPPORT
12 #  include <boost/concept/detail/has_constraints.hpp>
13 #  include <boost/type_traits/conditional.hpp>
14 # endif
15 
16 // This implementation works on Comeau and GCC, all the way back to
17 // 2.95
18 namespace boost { namespace concepts {
19 
20 template <class ModelFn>
21 struct requirement_;
22 
23 namespace detail
24 {
25   template <void(*)()> struct instantiate {};
26 }
27 
28 template <class Model>
29 struct requirement
30 {
31 #   if defined(BOOST_GCC) && (BOOST_GCC >= 110000)
32 #   pragma GCC diagnostic push
33 #   pragma GCC diagnostic ignored "-Wnonnull"
34 #   endif
failedboost::concepts::requirement35     static void failed() { ((Model*)0)->~Model(); }
36 #   if defined(BOOST_GCC) && (BOOST_GCC >= 110000)
37 #   pragma GCC diagnostic pop
38 #   endif
39 };
40 
41 struct failed {};
42 
43 template <class Model>
44 struct requirement<failed ************ Model::************>
45 {
46 #   if defined(BOOST_GCC) && (BOOST_GCC >= 110000)
47 #   pragma GCC diagnostic push
48 #   pragma GCC diagnostic ignored "-Wnonnull"
49 #   endif
failedboost::concepts::requirement50     static void failed() { ((Model*)0)->~Model(); }
51 #   if defined(BOOST_GCC) && (BOOST_GCC >= 110000)
52 #   pragma GCC diagnostic pop
53 #   endif
54 };
55 
56 # ifdef BOOST_OLD_CONCEPT_SUPPORT
57 
58 template <class Model>
59 struct constraint
60 {
61 #   if defined(BOOST_GCC) && (BOOST_GCC >= 110000)
62 #   pragma GCC diagnostic push
63 #   pragma GCC diagnostic ignored "-Wnonnull"
64 #   endif
failedboost::concepts::constraint65     static void failed() { ((Model*)0)->constraints(); }
66 #   if defined(BOOST_GCC) && (BOOST_GCC >= 110000)
67 #   pragma GCC diagnostic pop
68 #   endif
69 };
70 
71 template <class Model>
72 struct requirement_<void(*)(Model)>
73   : boost::conditional<
74         concepts::not_satisfied<Model>::value
75       , constraint<Model>
76       , requirement<failed ************ Model::************>
77     >::type
78 {};
79 
80 # else
81 
82 // For GCC-2.x, these can't have exactly the same name
83 template <class Model>
84 struct requirement_<void(*)(Model)>
85     : requirement<failed ************ Model::************>
86 {};
87 
88 # endif
89 
90 #  define BOOST_CONCEPT_ASSERT_FN( ModelFnPtr )             \
91     typedef ::boost::concepts::detail::instantiate<          \
92     &::boost::concepts::requirement_<ModelFnPtr>::failed>    \
93       BOOST_PP_CAT(boost_concept_check,__LINE__)             \
94       BOOST_ATTRIBUTE_UNUSED
95 
96 }}
97 
98 #endif // BOOST_CONCEPT_DETAIL_GENERAL_DWA2006429_HPP
99