59 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++11, c++14, c++17, c++2010 11// <mdspan>12 13// constexpr mapping(const extents_type&) noexcept;14//15// Preconditions: The size of the multidimensional index space e is representable16// as a value of type index_type ([basic.fundamental]).17//18// Effects: Direct-non-list-initializes extents_ with e.19 20#include <cassert>21#include <cstddef>22#include <cstdint>23#include <mdspan>24 25#include "test_macros.h"26 27template <class E>28constexpr void test_construction(E e) {29 using M = std::layout_left::mapping<E>;30 ASSERT_NOEXCEPT(M{e});31 M m(e);32 33 // check correct extents are returned34 ASSERT_NOEXCEPT(m.extents());35 assert(m.extents() == e);36 37 // check required_span_size()38 typename E::index_type expected_size = 1;39 for (typename E::rank_type r = 0; r < E::rank(); r++)40 expected_size *= e.extent(r);41 assert(m.required_span_size() == expected_size);42}43 44constexpr bool test() {45 constexpr size_t D = std::dynamic_extent;46 test_construction(std::extents<int>());47 test_construction(std::extents<unsigned, D>(7));48 test_construction(std::extents<unsigned, 7>());49 test_construction(std::extents<unsigned, 7, 8>());50 test_construction(std::extents<int64_t, D, 8, D, D>(7, 9, 10));51 return true;52}53 54int main(int, char**) {55 test();56 static_assert(test());57 return 0;58}59