1
2// (C) Copyright Edward Diener 2019
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_DETAIL_UNION_HPP)
8#define BOOST_TTI_DETAIL_UNION_HPP
9
10#include <boost/mpl/and.hpp>
11#include <boost/mpl/apply.hpp>
12#include <boost/mpl/bool.hpp>
13#include <boost/mpl/eval_if.hpp>
14#include <boost/mpl/has_xxx.hpp>
15#include <boost/preprocessor/cat.hpp>
16#include <boost/tti/detail/ddeftype.hpp>
17#include <boost/tti/detail/dlambda.hpp>
18#include <boost/tti/detail/denclosing_type.hpp>
19#include <boost/tti/gen/namespace_gen.hpp>
20#include <boost/type_traits/is_union.hpp>
21
22#define BOOST_TTI_DETAIL_TRAIT_INVOKE_HAS_UNION(trait,name) \
23template<class BOOST_TTI_DETAIL_TP_T,class BOOST_TTI_DETAIL_TP_MFC> \
24struct BOOST_PP_CAT(trait,_detail_union_invoke) \
25 { \
26 BOOST_MPL_ASSERT((BOOST_TTI_NAMESPACE::detail::is_lambda_expression<BOOST_TTI_DETAIL_TP_MFC>)); \
27 typedef typename boost::mpl::apply<BOOST_TTI_DETAIL_TP_MFC,typename BOOST_TTI_DETAIL_TP_T::name>::type type; \
28 }; \
29/**/
30
31#define BOOST_TTI_DETAIL_TRAIT_HAS_UNION_OP_CHOOSE(trait,name) \
32BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(BOOST_PP_CAT(trait,_detail_union_mpl), name, false) \
33BOOST_TTI_DETAIL_TRAIT_INVOKE_HAS_UNION(trait,name) \
34template<class BOOST_TTI_DETAIL_TP_T,class BOOST_TTI_DETAIL_TP_U,class BOOST_TTI_DETAIL_TP_B> \
35struct BOOST_PP_CAT(trait,_detail_union_op_choose) : \
36 boost::mpl::and_ \
37 < \
38 boost::is_union<typename BOOST_TTI_DETAIL_TP_T::name>, \
39 BOOST_PP_CAT(trait,_detail_union_invoke)<BOOST_TTI_DETAIL_TP_T,BOOST_TTI_DETAIL_TP_U> \
40 > \
41 { \
42 }; \
43\
44template<class BOOST_TTI_DETAIL_TP_T,class BOOST_TTI_DETAIL_TP_U> \
45struct BOOST_PP_CAT(trait,_detail_union_op_choose)<BOOST_TTI_DETAIL_TP_T,BOOST_TTI_DETAIL_TP_U,boost::mpl::false_::type> : \
46 boost::mpl::false_ \
47 { \
48 }; \
49\
50template<class BOOST_TTI_DETAIL_TP_T> \
51struct BOOST_PP_CAT(trait,_detail_union_op_choose)<BOOST_TTI_DETAIL_TP_T,BOOST_TTI_NAMESPACE::detail::deftype,boost::mpl::true_::type> : \
52 boost::is_union<typename BOOST_TTI_DETAIL_TP_T::name> \
53 { \
54 }; \
55/**/
56
57#define BOOST_TTI_DETAIL_TRAIT_HAS_UNION_OP(trait,name) \
58BOOST_TTI_DETAIL_TRAIT_HAS_UNION_OP_CHOOSE(trait,name) \
59template<class BOOST_TTI_DETAIL_TP_T,class BOOST_TTI_DETAIL_TP_U> \
60struct BOOST_PP_CAT(trait,_detail_union_op) : \
61 BOOST_PP_CAT(trait,_detail_union_op_choose) \
62 < \
63 BOOST_TTI_DETAIL_TP_T, \
64 BOOST_TTI_DETAIL_TP_U, \
65 typename BOOST_PP_CAT(trait,_detail_union_mpl)<BOOST_TTI_DETAIL_TP_T>::type \
66 > \
67 { \
68 }; \
69/**/
70
71#define BOOST_TTI_DETAIL_TRAIT_HAS_UNION(trait,name) \
72BOOST_TTI_DETAIL_TRAIT_HAS_UNION_OP(trait,name) \
73template<class BOOST_TTI_DETAIL_TP_T,class BOOST_TTI_DETAIL_TP_U> \
74struct BOOST_PP_CAT(trait,_detail_union) : \
75 boost::mpl::eval_if \
76 < \
77 BOOST_TTI_NAMESPACE::detail::enclosing_type<BOOST_TTI_DETAIL_TP_T>, \
78 BOOST_PP_CAT(trait,_detail_union_op)<BOOST_TTI_DETAIL_TP_T,BOOST_TTI_DETAIL_TP_U>, \
79 boost::mpl::false_ \
80 > \
81 { \
82 }; \
83/**/
84
85#endif // BOOST_TTI_DETAIL_UNION_HPP
86

source code of boost/libs/tti/include/boost/tti/detail/dunion.hpp