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
|
//===----------------------------------------------------------------------===//
//
// 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, c++11, c++14, c++17, c++20
// <mdspan>
//
// Test converting constructor:
//
// template<class OtherElementType>
// constexpr default_accessor(default_accessor<OtherElementType>) noexcept {}
//
// Constraints: is_convertible_v<OtherElementType(*)[], element_type(*)[]> is true.
#include <mdspan>
#include <cassert>
#include <cstdint>
#include <type_traits>
#include "test_macros.h"
#include "../MinimalElementType.h"
struct Base {};
struct Derived: public Base {};
template <class FromT, class ToT>
constexpr void test_conversion() {
std::default_accessor<FromT> acc_from;
ASSERT_NOEXCEPT(std::default_accessor<ToT>(acc_from));
[[maybe_unused]] std::default_accessor<ToT> acc_to(acc_from);
}
constexpr bool test() {
// default accessor conversion largely behaves like pointer conversion
test_conversion<int, int>();
test_conversion<int, const int>();
test_conversion<const int, const int>();
test_conversion<MinimalElementType, MinimalElementType>();
test_conversion<MinimalElementType, const MinimalElementType>();
test_conversion<const MinimalElementType, const MinimalElementType>();
// char is convertible to int, but accessors are not
static_assert(!std::is_constructible_v<std::default_accessor<int>, std::default_accessor<char>>);
// don't allow conversion from const elements to non-const
static_assert(!std::is_constructible_v<std::default_accessor<int>, std::default_accessor<const int>>);
// MinimalElementType is constructible from int, but accessors should not be convertible
static_assert(!std::is_constructible_v<std::default_accessor<MinimalElementType>, std::default_accessor<int>>);
// don't allow conversion from const elements to non-const
static_assert(!std::is_constructible_v<std::default_accessor<MinimalElementType>, std::default_accessor<const MinimalElementType>>);
// don't allow conversion from Base to Derived
static_assert(!std::is_constructible_v<std::default_accessor<Derived>, std::default_accessor<Base>>);
// don't allow conversion from Derived to Base
static_assert(!std::is_constructible_v<std::default_accessor<Base>, std::default_accessor<Derived>>);
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
|
