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 | |