has_member_qualifiers.hpp
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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_HAS_MEMBER_QUALIFIERS_HPP
10 #define BOOST_CLBL_TRTS_HAS_MEMBER_QUALIFIERS_HPP
11 
13 
14 namespace boost { namespace callable_traits {
15 
16 //[ has_member_qualifiers_hpp
17 /*`[section:ref_has_member_qualifiers has_member_qualifiers]
18 [heading Header]
19 ``#include <boost/callable_traits/has_member_qualifiers.hpp>``
20 [heading Definition]
21 */
22 
23 // inherits from either std::true_type or std::false_type
24 template<typename T>
25 struct has_member_qualifiers;
26 
27 //<-
28 template<typename T>
30  detail::shallow_decay<T>>::has_member_qualifiers {
31 
32  using type = typename detail::traits<
34 };
35 
36 // older compilers don't support variable templates
37 #ifdef BOOST_CLBL_TRTS_DISABLE_VARIABLE_TEMPLATES
38 
39 template<typename T>
41  static_assert(std::is_same<T, detail::dummy>::value,
42  "Variable templates not supported on this compiler.");
43 };
44 
45 #else
46 //->
47 // only available when variable templates are supported
48 template<typename T>
49 //<-
51 //->
52 constexpr bool has_member_qualifiers_v = //see below
53 //<-
54  detail::traits<detail::shallow_decay<T>>::has_member_qualifiers::value;
55 
56 #endif
57 
58 }} // namespace boost::callable_traits
59 //->
60 
61 /*`
62 [heading Constraints]
63 * none
64 
65 [heading Behavior]
66 * `std::false_type` is inherited by `has_member_qualifiers<T>` and is aliased by `typename has_member_qualifiers<T>::type`, except when one of the following criteria is met, in which case `std::true_type` would be similarly inherited and aliased:
67  * `T` is a function with member qualifiers
68  * `T` is a member function pointer with member qualifiers
69  * `T` is a function object with a member-qualified `operator()`
70 * On compilers that support variable templates, `has_member_qualifiers_v<T>` is equivalent to `has_member_qualifiers<T>::value`.
71 
72 [heading Input/Output Examples]
73 [table
74  [[`T`] [`has_member_qualifiers_v<T>`]]
75  [[`void() const`] [`true`]]
76  [[`void() const transaction_safe`] [`true`]]
77  [[`void() volatile &&`] [`true`]]
78  [[`int(foo::*)() &`] [`true`]]
79  [[`void(foo::*)() const`] [`true`]]
80  [[`void(foo::*&)() const`] [`true`]]
81  [[`void(foo::* const)() const`] [`true`]]
82  [[`void()`] [`false`]]
83  [[`void() transaction_safe`] [`false`]]
84  [[`void(*)()`] [`false`]]
85  [[`void(*&)()`] [`false`]]
86  [[`int`] [`false`]]
87  [[`const int`] [`false`]]
88  [[`int foo::*`] [`false`]]
89  [[`const int foo::*`] [`false`]]
90 ]
91 
92 [heading Example Program]
93 [import ../example/has_member_qualifiers.cpp]
94 [has_member_qualifiers]
95 [endsect]
96 */
97 //]
98 
99 #endif //BOOST_CLBL_TRTS_HAS_MEMBER_QUALIFIERS_HPP
#define BOOST_CLBL_TRAITS_INLINE_VAR
Definition: config.hpp:27
typename std::remove_cv< typename std::remove_reference< T >::type >::type shallow_decay
Definition: utility.hpp:79
typename BOOST_CLBL_TRTS_DISJUNCTION(function_object< unwrap_reference< T > >, function< T >, pmf< T >, pmd< T >, default_callable_traits< T >)::traits traits
Definition: traits.hpp:25
constexpr BOOST_CLBL_TRAITS_INLINE_VAR bool has_member_qualifiers_v
typename detail::traits< detail::shallow_decay< T > >::has_member_qualifiers type