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
9// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
10
11// <mdspan>
12
13// constexpr mapping(const extents_type&) noexcept;
14//
15// Preconditions: The size of the multidimensional index space e is representable
16// as a value of type index_type ([basic.fundamental]).
17//
18// Effects: Direct-non-list-initializes extents_ with e.
19
20#include <mdspan>
21#include <cassert>
22#include <cstdint>
23
24#include "test_macros.h"
25
26template <class E>
27constexpr void test_construction(E e) {
28 using M = std::layout_left::mapping<E>;
29 ASSERT_NOEXCEPT(M{e});
30 M m(e);
31
32 // check correct extents are returned
33 ASSERT_NOEXCEPT(m.extents());
34 assert(m.extents() == e);
35
36 // check required_span_size()
37 typename E::index_type expected_size = 1;
38 for (typename E::rank_type r = 0; r < E::rank(); r++)
39 expected_size *= e.extent(r);
40 assert(m.required_span_size() == expected_size);
41}
42
43constexpr bool test() {
44 constexpr size_t D = std::dynamic_extent;
45 test_construction(std::extents<int>());
46 test_construction(std::extents<unsigned, D>(7));
47 test_construction(std::extents<unsigned, 7>());
48 test_construction(std::extents<unsigned, 7, 8>());
49 test_construction(std::extents<int64_t, D, 8, D, D>(7, 9, 10));
50 return true;
51}
52
53int main(int, char**) {
54 test();
55 static_assert(test());
56 return 0;
57}
58

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