1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
9
10// <mdspan>
11
12// template <class... Integrals>
13// explicit extents(Integrals...) -> see below;
14// Constraints: (is_convertible_v<Integrals, size_t> && ...) is true.
15//
16// Remarks: The deduced type is dextents<size_t, sizeof...(Integrals)>. // until C++26
17// Remarks: The deduced type is extents<size_t, maybe-static-ext<Integrals>...>. // since C++26
18
19#include <cassert>
20#include <cstddef>
21#include <mdspan>
22#include <type_traits>
23
24#include "../ConvertibleToIntegral.h"
25#include "test_macros.h"
26
27struct NoDefaultCtorIndex {
28 size_t value;
29 constexpr NoDefaultCtorIndex() = delete;
30 constexpr NoDefaultCtorIndex(size_t val) : value(val) {}
31 constexpr operator size_t() const noexcept { return value; }
32};
33
34template <class E, class Expected>
35constexpr void test(E e, Expected expected) {
36 ASSERT_SAME_TYPE(E, Expected);
37 assert(e == expected);
38}
39
40constexpr bool test() {
41 constexpr std::size_t D = std::dynamic_extent;
42
43 test(std::extents(), std::extents<size_t>());
44 test(std::extents(1), std::extents<std::size_t, D>(1));
45 test(std::extents(1, 2u), std::extents<std::size_t, D, D>(1, 2u));
46 test(std::extents(1, 2u, 3, 4, 5, 6, 7, 8, 9),
47 std::extents<std::size_t, D, D, D, D, D, D, D, D, D>(1, 2u, 3, 4, 5, 6, 7, 8, 9));
48 test(std::extents(NoDefaultCtorIndex{1}, NoDefaultCtorIndex{2}), std::extents<std::size_t, D, D>(1, 2));
49
50#if _LIBCPP_STD_VER >= 26
51 // P3029R1: deduction from `integral_constant`
52 test(std::extents(std::integral_constant<size_t, 5>{}), std::extents<std::size_t, 5>());
53 test(std::extents(std::integral_constant<size_t, 5>{}, 6), std::extents<std::size_t, 5, std::dynamic_extent>(6));
54 test(std::extents(std::integral_constant<size_t, 5>{}, 6, std::integral_constant<size_t, 7>{}),
55 std::extents<std::size_t, 5, std::dynamic_extent, 7>(6));
56#endif
57
58 return true;
59}
60
61int main(int, char**) {
62 test();
63 static_assert(test());
64
65 return 0;
66}
67

source code of libcxx/test/std/containers/views/mdspan/extents/ctad.pass.cpp