1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
/*!
@file
Defines concepts from the Standard library.
@copyright Louis Dionne 2013-2016
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
*/
#ifndef BOOST_HANA_DETAIL_CONCEPTS_HPP
#define BOOST_HANA_DETAIL_CONCEPTS_HPP
#include <boost/hana/config.hpp>
#include <boost/hana/detail/std_common_type.hpp>
#include <boost/hana/detail/void_t.hpp>
#include <type_traits>
BOOST_HANA_NAMESPACE_BEGIN namespace detail {
//! @cond
//////////////////////////////////////////////////////////////////////////
// EqualityComparable
//////////////////////////////////////////////////////////////////////////
template <typename T, typename U = T, typename = void>
struct EqualityComparable : std::false_type { };
template <typename T>
struct EqualityComparable<T, T, detail::void_t<
decltype(static_cast<T&&>(*(T*)0) == static_cast<T&&>(*(T*)0) ? 0:0),
decltype(static_cast<T&&>(*(T*)0) != static_cast<T&&>(*(T*)0) ? 0:0)
>> : std::true_type { };
template <typename T, typename U>
struct EqualityComparable<T, U, typename std::enable_if<
!std::is_same<T, U>::value, detail::void_t<
decltype(static_cast<T&&>(*(T*)0) == static_cast<U&&>(*(U*)0) ? 0:0),
decltype(static_cast<U&&>(*(U*)0) == static_cast<T&&>(*(T*)0) ? 0:0),
decltype(static_cast<T&&>(*(T*)0) != static_cast<U&&>(*(U*)0) ? 0:0),
decltype(static_cast<U&&>(*(U*)0) != static_cast<T&&>(*(T*)0) ? 0:0),
typename detail::std_common_type<T, U>::type
>>::type> : std::integral_constant<bool,
EqualityComparable<T>::value &&
EqualityComparable<U>::value &&
EqualityComparable<typename detail::std_common_type<T, U>::type>::value
> { };
//////////////////////////////////////////////////////////////////////////
// LessThanComparable
//////////////////////////////////////////////////////////////////////////
template <typename T, typename U = T, typename = void>
struct LessThanComparable : std::false_type { };
template <typename T>
struct LessThanComparable<T, T, detail::void_t<
decltype(static_cast<T&&>(*(T*)0) < static_cast<T&&>(*(T*)0) ? 0:0)
>> : std::true_type { };
template <typename T, typename U>
struct LessThanComparable<T, U, std::enable_if_t<
!std::is_same<T, U>::value,
detail::void_t<
decltype(static_cast<T&&>(*(T*)0) < static_cast<U&&>(*(U*)0) ? 0:0),
decltype(static_cast<U&&>(*(U*)0) < static_cast<T&&>(*(T*)0) ? 0:0),
typename detail::std_common_type<T, U>::type
>
>>
: std::integral_constant<bool,
LessThanComparable<T>::value &&
LessThanComparable<U>::value &&
LessThanComparable<typename detail::std_common_type<T, U>::type>::value
>
{ };
//! @endcond
} BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_DETAIL_CONCEPTS_HPP
|
