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1 | // Copyright David Abrahams 2005. |
2 | // Distributed under the Boost Software License, Version 1.0. | |
3 | // (See accompanying file LICENSE_1_0.txt or copy at | |
4 | // http://www.boost.org/LICENSE_1_0.txt) | |
5 | ||
7c673cae | 6 | #ifndef BOOST_PARAMETER_BINDING_DWA200558_HPP |
92f5a8d4 TL |
7 | #define BOOST_PARAMETER_BINDING_DWA200558_HPP |
8 | ||
9 | #include <boost/parameter/aux_/void.hpp> | |
10 | #include <boost/parameter/config.hpp> | |
7c673cae | 11 | |
92f5a8d4 TL |
12 | #if defined(BOOST_PARAMETER_CAN_USE_MP11) |
13 | #include <boost/mp11/integral.hpp> | |
14 | #include <boost/mp11/list.hpp> | |
15 | #include <boost/mp11/utility.hpp> | |
16 | #include <type_traits> | |
17 | #else | |
18 | #include <boost/mpl/bool.hpp> | |
19 | #include <boost/mpl/if.hpp> | |
20 | #include <boost/mpl/eval_if.hpp> | |
21 | #include <boost/mpl/identity.hpp> | |
22 | #include <boost/mpl/apply_wrap.hpp> | |
23 | #include <boost/mpl/assert.hpp> | |
24 | #include <boost/type_traits/is_same.hpp> | |
25 | #endif | |
7c673cae FG |
26 | |
27 | namespace boost { namespace parameter { | |
28 | ||
92f5a8d4 TL |
29 | // A metafunction that, given an argument pack, returns the reference type |
30 | // of the parameter identified by the given keyword. If no such parameter | |
31 | // has been specified, returns Default | |
32 | ||
33 | template <typename Parameters, typename Keyword, typename Default> | |
34 | struct binding0 | |
35 | { | |
36 | #if defined(BOOST_PARAMETER_CAN_USE_MP11) | |
37 | using type = ::boost::mp11::mp_apply_q< | |
38 | typename Parameters::binding | |
39 | , ::boost::mp11::mp_list<Keyword,Default,::boost::mp11::mp_true> | |
40 | >; | |
41 | ||
42 | static_assert( | |
43 | ::boost::mp11::mp_if< | |
44 | ::std::is_same<Default,::boost::parameter::void_> | |
45 | , ::boost::mp11::mp_if< | |
46 | ::std::is_same<type,::boost::parameter::void_> | |
47 | , ::boost::mp11::mp_false | |
48 | , ::boost::mp11::mp_true | |
49 | > | |
50 | , ::boost::mp11::mp_true | |
51 | >::value | |
52 | , "required parameters must not result in void_ type" | |
53 | ); | |
54 | #else // !defined(BOOST_PARAMETER_CAN_USE_MP11) | |
55 | typedef typename ::boost::mpl::apply_wrap3< | |
56 | typename Parameters::binding | |
57 | , Keyword | |
58 | , Default | |
59 | , ::boost::mpl::true_ | |
60 | >::type type; | |
61 | ||
62 | BOOST_MPL_ASSERT(( | |
63 | typename ::boost::mpl::eval_if< | |
64 | ::boost::is_same<Default,::boost::parameter::void_> | |
65 | , ::boost::mpl::if_< | |
66 | ::boost::is_same<type,::boost::parameter::void_> | |
67 | , ::boost::mpl::false_ | |
68 | , ::boost::mpl::true_ | |
69 | > | |
70 | , ::boost::mpl::true_ | |
71 | >::type | |
72 | )); | |
73 | #endif // BOOST_PARAMETER_CAN_USE_MP11 | |
74 | }; | |
75 | ||
76 | #if defined(BOOST_PARAMETER_CAN_USE_MP11) | |
77 | template <typename Placeholder, typename Keyword, typename Default> | |
78 | struct binding1 | |
79 | { | |
80 | using type = ::boost::mp11::mp_apply_q< | |
81 | Placeholder | |
82 | , ::boost::mp11::mp_list<Keyword,Default,::boost::mp11::mp_true> | |
83 | >; | |
84 | ||
85 | static_assert( | |
86 | ::boost::mp11::mp_if< | |
87 | ::std::is_same<Default,::boost::parameter::void_> | |
88 | , ::boost::mp11::mp_if< | |
89 | ::std::is_same<type,::boost::parameter::void_> | |
90 | , ::boost::mp11::mp_false | |
91 | , ::boost::mp11::mp_true | |
92 | > | |
93 | , ::boost::mp11::mp_true | |
94 | >::value | |
95 | , "required parameters must not result in void_ type" | |
96 | ); | |
97 | }; | |
98 | #endif // BOOST_PARAMETER_CAN_USE_MP11 | |
99 | }} // namespace boost::parameter | |
100 | ||
101 | #include <boost/parameter/aux_/is_placeholder.hpp> | |
102 | ||
103 | namespace boost { namespace parameter { | |
104 | ||
105 | template < | |
106 | typename Parameters | |
107 | , typename Keyword | |
108 | , typename Default = ::boost::parameter::void_ | |
109 | > | |
110 | struct binding | |
111 | #if !defined(BOOST_PARAMETER_CAN_USE_MP11) | |
112 | : ::boost::mpl::eval_if< | |
113 | ::boost::parameter::aux::is_mpl_placeholder<Parameters> | |
114 | , ::boost::mpl::identity<int> | |
115 | , ::boost::parameter::binding0<Parameters,Keyword,Default> | |
7c673cae | 116 | > |
92f5a8d4 TL |
117 | #endif |
118 | { | |
119 | #if defined(BOOST_PARAMETER_CAN_USE_MP11) | |
120 | using type = typename ::boost::mp11::mp_if< | |
121 | ::boost::parameter::aux::is_mpl_placeholder<Parameters> | |
122 | , ::boost::mp11::mp_identity<int> | |
123 | , ::boost::mp11::mp_if< | |
124 | ::boost::parameter::aux::is_mp11_placeholder<Parameters> | |
125 | , ::boost::parameter::binding1<Parameters,Keyword,Default> | |
126 | , ::boost::parameter::binding0<Parameters,Keyword,Default> | |
127 | > | |
128 | >::type; | |
129 | #endif | |
130 | }; | |
131 | }} // namespace boost::parameter | |
132 | ||
133 | #include <boost/parameter/aux_/result_of0.hpp> | |
7c673cae | 134 | |
92f5a8d4 | 135 | namespace boost { namespace parameter { |
7c673cae | 136 | |
92f5a8d4 TL |
137 | // A metafunction that, given an argument pack, returns the reference type |
138 | // of the parameter identified by the given keyword. If no such parameter | |
139 | // has been specified, returns the type returned by invoking DefaultFn | |
140 | template <typename Parameters, typename Keyword, typename DefaultFn> | |
141 | struct lazy_binding | |
142 | { | |
143 | #if defined(BOOST_PARAMETER_CAN_USE_MP11) | |
144 | using type = ::boost::mp11::mp_apply_q< | |
145 | typename Parameters::binding | |
146 | , ::boost::mp11::mp_list< | |
147 | Keyword | |
148 | , typename ::boost::parameter::aux::result_of0<DefaultFn>::type | |
149 | , ::boost::mp11::mp_true | |
150 | > | |
151 | >; | |
152 | #else | |
153 | typedef typename ::boost::mpl::apply_wrap3< | |
154 | typename Parameters::binding | |
155 | , Keyword | |
156 | , typename ::boost::parameter::aux::result_of0<DefaultFn>::type | |
157 | , ::boost::mpl::true_ | |
158 | >::type type; | |
159 | #endif // BOOST_PARAMETER_CAN_USE_MP11 | |
160 | }; | |
7c673cae FG |
161 | }} // namespace boost::parameter |
162 | ||
92f5a8d4 TL |
163 | #endif // include guard |
164 |