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 index_type stride(rank_type i) const noexcept;14//15// Constraints: extents_type::rank() > 0 is true.16//17// Preconditions: i < extents_type::rank() is true.18//19// Returns: extents().rev-prod-of-extents(i).20 21#include <mdspan>22#include <array>23#include <cassert>24#include <cstdint>25#include <cstdio>26 27#include "test_macros.h"28 29template <class E, class... Args>30constexpr void test_stride(std::array<typename E::index_type, E::rank()> strides, Args... args) {31 using M = std::layout_stride::mapping<E>;32 M m(E(args...), strides);33 34 ASSERT_NOEXCEPT(m.stride(0));35 for (size_t r = 0; r < E::rank(); r++)36 assert(strides[r] == m.stride(r));37 38 ASSERT_NOEXCEPT(m.strides());39 auto strides_out = m.strides();40 static_assert(std::is_same_v<decltype(strides_out), std::array<typename E::index_type, E::rank()>>);41 for (size_t r = 0; r < E::rank(); r++)42 assert(strides[r] == strides_out[r]);43}44 45constexpr bool test() {46 constexpr size_t D = std::dynamic_extent;47 test_stride<std::extents<unsigned, D>>(std::array<unsigned, 1>{1}, 7);48 test_stride<std::extents<unsigned, 7>>(std::array<unsigned, 1>{1});49 test_stride<std::extents<unsigned, 7, 8>>(std::array<unsigned, 2>{8, 1});50 test_stride<std::extents<int64_t, D, 8, D, D>>(std::array<int64_t, 4>{720, 90, 10, 1}, 7, 9, 10);51 return true;52}53 54int main(int, char**) {55 test();56 static_assert(test());57 return 0;58}59