1 | |
2 | // (C) Copyright Edward Diener 2012,2013 |
3 | // Use, modification and distribution are subject to the Boost Software License, |
4 | // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
5 | // http://www.boost.org/LICENSE_1_0.txt). |
6 | |
7 | #if !defined(BOOST_TTI_HAS_DATA_HPP) |
8 | #define BOOST_TTI_HAS_DATA_HPP |
9 | |
10 | #include <boost/config.hpp> |
11 | #include <boost/preprocessor/cat.hpp> |
12 | #include <boost/type_traits/remove_const.hpp> |
13 | #include <boost/tti/gen/has_data_gen.hpp> |
14 | #include <boost/tti/detail/ddata.hpp> |
15 | |
16 | /* |
17 | |
18 | The succeeding comments in this file are in doxygen format. |
19 | |
20 | */ |
21 | |
22 | /** \file |
23 | */ |
24 | |
25 | /// Expands to a metafunction which tests whether member data or static member with a particular name and type exists. |
26 | /** |
27 | |
28 | trait = the name of the metafunction. |
29 | |
30 | name = the name of the inner member to introspect. |
31 | |
32 | generates a metafunction called "trait" where 'trait' is the macro parameter. |
33 | |
34 | template<class BOOST_TTI_TP_T,class BOOST_TTI_TP_TYPE> |
35 | struct trait |
36 | { |
37 | static const value = unspecified; |
38 | typedef mpl::bool_<true-or-false> type; |
39 | }; |
40 | |
41 | The metafunction types and return: |
42 | |
43 | BOOST_TTI_TP_T = the enclosing type in which to look for our 'name' |
44 | |
45 | BOOST_TTI_TP_TYPE = The type of the member data or static member. |
46 | |
47 | returns = 'value' is true if the 'name' exists, with the correct data type, |
48 | otherwise 'value' is false. |
49 | |
50 | */ |
51 | #define BOOST_TTI_TRAIT_HAS_DATA(trait,name) \ |
52 | BOOST_TTI_DETAIL_TRAIT_HAS_DATA(trait,name) \ |
53 | template<class BOOST_TTI_TP_T,class BOOST_TTI_TP_TYPE> \ |
54 | struct trait \ |
55 | { \ |
56 | typedef typename \ |
57 | BOOST_PP_CAT(trait,_detail_hd) \ |
58 | < \ |
59 | typename boost::remove_const<BOOST_TTI_TP_T>::type, \ |
60 | BOOST_TTI_TP_TYPE \ |
61 | >::type type; \ |
62 | BOOST_STATIC_CONSTANT(bool,value=type::value); \ |
63 | }; \ |
64 | /**/ |
65 | |
66 | /// Expands to a metafunction which tests whether member data or static member data with a particular name and type exists. |
67 | /** |
68 | |
69 | name = the name of the inner member. |
70 | |
71 | generates a metafunction called "has_data_name" where 'name' is the macro parameter. |
72 | |
73 | template<class BOOST_TTI_TP_T,class BOOST_TTI_TP_TYPE> |
74 | struct has_data_name |
75 | { |
76 | static const value = unspecified; |
77 | typedef mpl::bool_<true-or-false> type; |
78 | }; |
79 | |
80 | The metafunction types and return: |
81 | |
82 | BOOST_TTI_TP_T = the enclosing type in which to look for our 'name' |
83 | |
84 | BOOST_TTI_TP_TYPE = The type of the member data or static member. |
85 | |
86 | returns = 'value' is true if the 'name' exists, with the correct data type, |
87 | otherwise 'value' is false. |
88 | |
89 | */ |
90 | #define BOOST_TTI_HAS_DATA(name) \ |
91 | BOOST_TTI_TRAIT_HAS_DATA \ |
92 | ( \ |
93 | BOOST_TTI_HAS_DATA_GEN(name), \ |
94 | name \ |
95 | ) \ |
96 | /**/ |
97 | |
98 | #endif // BOOST_TTI_HAS_DATA_HPP |
99 | |