PR31384.pass.cpp
2.24 KB
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
81
82
83
84
85
86
87
88
89
90
91
// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03
// <tuple>
// template <class TupleLike> tuple(TupleLike&&); // libc++ extension
// See llvm.org/PR31384
#include <tuple>
#include <cassert>
#include "test_macros.h"
int count = 0;
struct Explicit {
Explicit() = default;
explicit Explicit(int) {}
};
struct Implicit {
Implicit() = default;
Implicit(int) {}
};
template<class T>
struct Derived : std::tuple<T> {
using std::tuple<T>::tuple;
template<class U>
operator std::tuple<U>() && { ++count; return {}; }
};
template<class T>
struct ExplicitDerived : std::tuple<T> {
using std::tuple<T>::tuple;
template<class U>
explicit operator std::tuple<U>() && { ++count; return {}; }
};
int main(int, char**) {
{
std::tuple<Explicit> foo = Derived<int>{42}; ((void)foo);
assert(count == 1);
std::tuple<Explicit> bar(Derived<int>{42}); ((void)bar);
assert(count == 2);
}
count = 0;
{
std::tuple<Implicit> foo = Derived<int>{42}; ((void)foo);
assert(count == 1);
std::tuple<Implicit> bar(Derived<int>{42}); ((void)bar);
assert(count == 2);
}
count = 0;
{
static_assert(!std::is_convertible<
ExplicitDerived<int>, std::tuple<Explicit>>::value, "");
std::tuple<Explicit> bar(ExplicitDerived<int>{42}); ((void)bar);
assert(count == 1);
}
count = 0;
{
// FIXME: Libc++ incorrectly rejects this code.
#ifndef _LIBCPP_VERSION
std::tuple<Implicit> foo = ExplicitDerived<int>{42}; ((void)foo);
static_assert(std::is_convertible<
ExplicitDerived<int>, std::tuple<Implicit>>::value,
"correct STLs accept this");
#else
static_assert(!std::is_convertible<
ExplicitDerived<int>, std::tuple<Implicit>>::value,
"libc++ incorrectly rejects this");
#endif
assert(count == 0);
std::tuple<Implicit> bar(ExplicitDerived<int>{42}); ((void)bar);
assert(count == 1);
}
count = 0;
return 0;
}