1 // Boost.TypeErasure library
2 //
3 // Copyright 2012 Steven Watanabe
4 //
5 // Distributed under the Boost Software License Version 1.0. (See
6 // accompanying file LICENSE_1_0.txt or copy at
7 // http://www.boost.org/LICENSE_1_0.txt)
8 //
9 // $Id$
10 
11 #if !defined(BOOST_PP_IS_ITERATING)
12 
13 #ifndef BOOST_TYPE_ERASURE_DETAIL_CHECK_CALL_HPP_INCLUDED
14 #define BOOST_TYPE_ERASURE_DETAIL_CHECK_CALL_HPP_INCLUDED
15 
16 #include <boost/mpl/eval_if.hpp>
17 #include <boost/mpl/bool.hpp>
18 #include <boost/mpl/and.hpp>
19 #include <boost/type_traits/is_convertible.hpp>
20 #include <boost/type_traits/remove_reference.hpp>
21 #include <boost/type_traits/remove_cv.hpp>
22 #include <boost/type_traits/is_reference.hpp>
23 #include <boost/type_traits/is_const.hpp>
24 #include <boost/type_traits/function_traits.hpp>
25 #include <boost/preprocessor/iteration/iterate.hpp>
26 #include <boost/preprocessor/repetition/enum_params.hpp>
27 #include <boost/preprocessor/repetition/enum_trailing_params.hpp>
28 #include <boost/preprocessor/repetition/repeat.hpp>
29 #include <boost/preprocessor/cat.hpp>
30 #include <boost/type_erasure/placeholder_of.hpp>
31 
32 namespace boost {
33 namespace type_erasure {
34 namespace detail {
35 
36 template<class Sig, class Args>
37 struct check_call : ::boost::mpl::false_ {};
38 
39 template<class T, class Enable = void>
40 struct qualified_placeholder
41 {
42     typedef void type;
43 };
44 
45 template<class T>
46 struct qualified_placeholder<T&, typename T::_boost_type_erasure_is_any>
47 {
48     typedef typename ::boost::type_erasure::placeholder_of<T>::type placeholder;
49     typedef typename ::boost::remove_reference<placeholder>::type unref;
50     typedef typename ::boost::mpl::if_< ::boost::is_const<T>,
51         const unref,
52         unref
53     >::type add_const;
54     typedef typename ::boost::mpl::if_< ::boost::is_reference<placeholder>,
55         placeholder,
56         add_const&
57     >::type type;
58 };
59 
60 #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
61 
62 template<class T>
63 struct qualified_placeholder<T&&, typename T::_boost_type_erasure_is_any>
64 {
65     typedef typename ::boost::type_erasure::placeholder_of<T>::type placeholder;
66     typedef placeholder&& type;
67 };
68 
69 #endif
70 
71 template<class P, class A>
72 struct check_placeholder_arg_impl : ::boost::mpl::false_ {};
73 
74 template<class P>
75 struct check_placeholder_arg_impl<P, P&> : ::boost::mpl::true_ {};
76 
77 template<class P>
78 struct check_placeholder_arg_impl<P, const P&> : ::boost::mpl::true_ {};
79 
80 #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
81 
82 template<class P>
83 struct check_placeholder_arg_impl<P, P&&> : ::boost::mpl::true_ {};
84 
85 #endif
86 
87 template<class P>
88 struct check_placeholder_arg_impl<P&, P&> : ::boost::mpl::true_ {};
89 
90 template<class P>
91 struct check_placeholder_arg_impl<const P&, P&> : ::boost::mpl::true_ {};
92 
93 template<class P>
94 struct check_placeholder_arg_impl<const P&, const P&> : ::boost::mpl::true_ {};
95 
96 #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
97 
98 template<class P>
99 struct check_placeholder_arg_impl<const P&, P&&> : ::boost::mpl::true_ {};
100 
101 template<class P>
102 struct check_placeholder_arg_impl<P&&, P&&> : ::boost::mpl::true_ {};
103 
104 #endif
105 
106 template<class P, class Arg>
107 struct check_placeholder_arg :
108     check_placeholder_arg_impl<
109         P,
110         typename ::boost::type_erasure::detail::qualified_placeholder<Arg>::type
111     >::type
112 {};
113 
114 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && \
115     ((defined(__GNUC__) && !(__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ > 6))) || \
116     defined(__MINGW32__) || defined(__MINGW64__))
117 #define BOOST_TYPE_ERASURE_BROKEN_RVALUE_IS_CONVERTIBLE
118 #endif
119 
120 template<class FormalArg, class ActualArg>
121 struct check_arg
122 {
123     typedef typename ::boost::mpl::eval_if<
124         is_placeholder<
125             typename ::boost::remove_cv<
126                 typename ::boost::remove_reference<FormalArg>::type
127             >::type
128         >,
129         ::boost::type_erasure::detail::check_placeholder_arg<FormalArg, ActualArg>,
130 #ifdef BOOST_TYPE_ERASURE_BROKEN_RVALUE_IS_CONVERTIBLE
131         ::boost::mpl::true_
132 #else
133         ::boost::is_convertible<ActualArg, FormalArg>
134 #endif
135     >::type type;
136 };
137 
138 #define BOOST_PP_FILENAME_1 <boost/type_erasure/detail/check_call.hpp>
139 #define BOOST_PP_ITERATION_LIMITS (0, BOOST_TYPE_ERASURE_MAX_ARITY)
140 #include BOOST_PP_ITERATE()
141 
142 }
143 }
144 }
145 
146 #endif
147 
148 #else
149 
150 #define N BOOST_PP_ITERATION()
151 
152 #define BOOST_TYPE_ERASURE_CHECK_ARG(z, n, data)                \
153     typedef typename ::boost::type_erasure::detail::check_arg<  \
154         BOOST_PP_CAT(T, n),                                     \
155         BOOST_PP_CAT(U, n)                                      \
156     >::type BOOST_PP_CAT(check, n);                             \
157     typedef typename ::boost::mpl::and_<                        \
158         BOOST_PP_CAT(type, n),                                  \
159         BOOST_PP_CAT(check, n)                                  \
160     >::type BOOST_PP_CAT(type, BOOST_PP_INC(n));
161 
162 template<
163     class R
164     BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)
165     BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)
166 >
167 struct check_call<R(BOOST_PP_ENUM_PARAMS(N, T)), void(BOOST_PP_ENUM_BINARY_PARAMS(N, U, u))> {
168     typedef ::boost::mpl::true_ type0;
169     BOOST_PP_REPEAT(N, BOOST_TYPE_ERASURE_CHECK_ARG, ~)
170     typedef BOOST_PP_CAT(type, N) type;
171 };
172 
173 #undef N
174 
175 #endif
176