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
79
80
|
// { dg-options "-std=gnu++17" }
// { dg-do compile { target c++17 } }
// Copyright (C) 2013-2019 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
#include <optional>
#include <testsuite_hooks.h>
namespace ns
{
struct value_type
{
int i;
const char* s;
};
constexpr bool
strcmp(const char* lhs, const char* rhs)
{
return *lhs == *rhs && (!*lhs || strcmp(lhs + 1, rhs + 1));
}
constexpr bool
strrel(const char* lhs, const char* rhs)
{
return (*rhs && (!*lhs || (*lhs < *rhs)))
|| ((*lhs && *rhs && !(*rhs < *lhs)) && strrel(lhs + 1, rhs + 1));
}
constexpr bool
operator==(value_type const& lhs, value_type const& rhs)
{ return (lhs.i == rhs.i) && strcmp(lhs.s, rhs.s); }
constexpr bool
operator!=(value_type const& lhs, value_type const& rhs)
{ return !(lhs == rhs); }
constexpr bool
operator<(value_type const& lhs, value_type const& rhs)
{ return (lhs.i < rhs.i) || (!(rhs.i < lhs.i) && strrel(lhs.s, rhs.s)); }
} // namespace ns
int main()
{
using ns::value_type;
using O = std::optional<value_type>;
using std::nullopt;
{
constexpr O o;
static_assert( o == nullopt, "" );
static_assert( nullopt == o, "" );
static_assert( !(o != nullopt), "" );
static_assert( !(nullopt != o), "" );
}
{
constexpr O o { std::in_place };
static_assert( !(o == nullopt), "" );
static_assert( !(nullopt == o), "" );
static_assert( o != nullopt, "" );
static_assert( nullopt != o, "" );
}
}
|
