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1 /*
2 
3 @Copyright Barrett Adair 2015-2017
4 Distributed under the Boost Software License, Version 1.0.
5 (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
6 
7 */
8 
9 #ifndef BOOST_CLBL_TRTS_ARGS_HPP
10 #define BOOST_CLBL_TRTS_ARGS_HPP
11 
12 #include <boost/callable_traits/detail/core.hpp>
13 
14 namespace boost { namespace callable_traits {
15 
16 //[ args_hpp
17 /*`[section:ref_args args]
18 [heading Header]
19 ``#include <boost/callable_traits/args.hpp>``
20 [heading Definition]
21 */
22 
23 template<typename T, template<class...> class Container = std::tuple>
24 using args_t = //see below
25 //<-
26     detail::try_but_fail_if_invalid<
27         typename detail::traits<
28             detail::shallow_decay<T>>::template expand_args<Container>,
29         cannot_expand_the_parameter_list_of_first_template_argument>;
30 
31 namespace detail {
32 
33     template<typename T, template<class...> class Container,
34         typename = std::false_type>
35     struct args_impl {};
36 
37     template<typename T, template<class...> class Container>
38     struct args_impl <T, Container, typename std::is_same<
39         args_t<T, Container>, detail::dummy>::type>
40     {
41         using type = args_t<T, Container>;
42     };
43 }
44 
45 //->
46 
47 template<typename T,
48     template<class...> class Container = std::tuple>
49 struct args : detail::args_impl<T, Container> {};
50 
51 //<-
52 }} // namespace boost::callable_traits
53 //->
54 
55 /*`
56 [heading Constraints]
57 * `T` must be one of the following:
58   * function
59   * function pointer
60   * function reference
61   * member function pointer
62   * member data pointer
63   * user-defined type with a non-overloaded `operator()`
64   * type of a non-generic lambda
65 
66 [heading Behavior]
67 * When the constraints are violated, a substitution failure occurs.
68 * When `T` is a function, function pointer, or function reference, the aliased type is `Container` instantiated with the function's parameter types.
69 * When `T` is a function object, the aliased type is `Container` instantiated with the `T::operator()` parameter types.
70 * When `T` is a member function pointer, the aliased type is a `Container` instantiation, where the first type argument is a reference to the parent class of `T`, qualified according to the member qualifiers on `T`, such that the first type is equivalent to `boost::callable_traits::qualified_class_of_t<T>`. The subsequent type arguments, if any, are the parameter types of the member function.
71 * When `T` is a member data pointer, the aliased type is `Container` with a single element, which is a `const` reference to the parent class of `T`.
72 
73 [heading Input/Output Examples]
74 [table
75     [[`T`]                              [`args_t<T>`]]
76     [[`void(float, char, int)`]         [`std::tuple<float, char, int>`]]
77     [[`void(*)(float, char, int)`]      [`std::tuple<float, char, int`]]
78     [[`void(&)(float, char, int)`]      [`std::tuple<float, char, int`]]
79     [[`void(float, char, int) const &&`][`std::tuple<float, char, int>`]]
80     [[`void(*)()`]                      [`std::tuple<>`]]
81     [[`void(foo::* const &)(float, char, int)`] [`std::tuple<foo&, float, char, int>`]]
82     [[`int(foo::*)(int) const`]         [`std::tuple<const foo&, int>`]]
83     [[`void(foo::*)() volatile &&`]     [`std::tuple<volatile foo &&>`]]
84     [[`int foo::*`]                     [`std::tuple<const foo&>`]]
85     [[`const int foo::*`]               [`std::tuple<const foo&>`]]
86     [[`int`]                            [(substitution failure)]]
87     [[`int (*const)()`]                 [(substitution failure)]]
88 ]
89 
90 [heading Example Program]
91 [import ../example/args.cpp]
92 [args]
93 [endsect]
94 */
95 //]
96 
97 #endif // #ifndef BOOST_CLBL_TRTS_ARGS_HPP
98