71 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++179 10// <span>11 12// [[nodiscard]] constexpr bool empty() const noexcept;13//14 15#include <span>16#include <cassert>17#include <string>18 19#include "test_macros.h"20 21struct A {};22constexpr int iArr1[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};23int iArr2[] = {10, 11, 12, 13, 14, 15, 16, 17, 18, 19};24 25int main(int, char**) {26 static_assert(noexcept(std::span<int>().empty()), "");27 static_assert(noexcept(std::span<int, 0>().empty()), "");28 29 static_assert(std::span<int>().empty(), "");30 static_assert(std::span<long>().empty(), "");31 static_assert(std::span<double>().empty(), "");32 static_assert(std::span<A>().empty(), "");33 static_assert(std::span<std::string>().empty(), "");34 35 static_assert(std::span<int, 0>().empty(), "");36 static_assert(std::span<long, 0>().empty(), "");37 static_assert(std::span<double, 0>().empty(), "");38 static_assert(std::span<A, 0>().empty(), "");39 static_assert(std::span<std::string, 0>().empty(), "");40 41 static_assert(!std::span<const int>(iArr1, 1).empty(), "");42 static_assert(!std::span<const int>(iArr1, 2).empty(), "");43 static_assert(!std::span<const int>(iArr1, 3).empty(), "");44 static_assert(!std::span<const int>(iArr1, 4).empty(), "");45 static_assert(!std::span<const int>(iArr1, 5).empty(), "");46 47 assert((std::span<int>().empty()));48 assert((std::span<long>().empty()));49 assert((std::span<double>().empty()));50 assert((std::span<A>().empty()));51 assert((std::span<std::string>().empty()));52 53 assert((std::span<int, 0>().empty()));54 assert((std::span<long, 0>().empty()));55 assert((std::span<double, 0>().empty()));56 assert((std::span<A, 0>().empty()));57 assert((std::span<std::string, 0>().empty()));58 59 assert(!(std::span<int, 1>(iArr2, 1).empty()));60 assert(!(std::span<int, 2>(iArr2, 2).empty()));61 assert(!(std::span<int, 3>(iArr2, 3).empty()));62 assert(!(std::span<int, 4>(iArr2, 4).empty()));63 assert(!(std::span<int, 5>(iArr2, 5).empty()));64 65 std::string s;66 assert(((std::span<std::string>(&s, (std::size_t)0)).empty()));67 assert(!((std::span<std::string>(&s, 1).empty())));68 69 return 0;70}71