67 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// UNSUPPORTED: c++03, c++11, c++14, c++17, c++209 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++2617// Remarks: The deduced type is extents<size_t, maybe-static-ext<Integrals>...>. // since C++2618 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 >= 2651 // 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#endif57 58 return true;59}60 61int main(int, char**) {62 test();63 static_assert(test());64 65 return 0;66}67