xref: /llvm-project/libcxx/test/std/containers/views/mdspan/layout_right/ctor.default.pass.cpp (revision e99c4906e44ae3f921fa05356909d006cda8d954)
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 // Test default construction:
14 //
15 // constexpr mapping() noexcept = default;
16 
17 #include <cassert>
18 #include <cstddef>
19 #include <cstdint>
20 #include <mdspan>
21 #include <span> // dynamic_extent
22 
23 #include "test_macros.h"
24 
25 template <class E>
26 constexpr void test_construction() {
27   using M = std::layout_right::mapping<E>;
28   ASSERT_NOEXCEPT(M{});
29   M m;
30   E 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 
43 constexpr bool test() {
44   constexpr size_t D = std::dynamic_extent;
45   test_construction<std::extents<int>>();
46   test_construction<std::extents<unsigned, D>>();
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>>();
50   return true;
51 }
52 
53 int main(int, char**) {
54   test();
55   static_assert(test());
56   return 0;
57 }
58