79 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// constexpr span() noexcept;13 14#include <span>15#include <cassert>16#include <string>17#include <type_traits>18 19#include "test_macros.h"20 21void checkCV() {22 // Types the same (dynamic sized)23 {24 std::span< int> s1;25 std::span<const int> s2;26 std::span< volatile int> s3;27 std::span<const volatile int> s4;28 assert(s1.size() + s2.size() + s3.size() + s4.size() == 0);29 }30 31 // Types the same (static sized)32 {33 std::span< int, 0> s1;34 std::span<const int, 0> s2;35 std::span< volatile int, 0> s3;36 std::span<const volatile int, 0> s4;37 assert(s1.size() + s2.size() + s3.size() + s4.size() == 0);38 }39}40 41template <typename T>42constexpr bool testConstexprSpan() {43 std::span<const T> s1;44 std::span<const T, 0> s2;45 return s1.data() == nullptr && s1.size() == 0 && s2.data() == nullptr && s2.size() == 0;46}47 48template <typename T>49void testRuntimeSpan() {50 ASSERT_NOEXCEPT(T{});51 std::span<const T> s1;52 std::span<const T, 0> s2;53 assert(s1.data() == nullptr && s1.size() == 0);54 assert(s2.data() == nullptr && s2.size() == 0);55}56 57struct A {};58 59int main(int, char**) {60 static_assert(testConstexprSpan<int>(), "");61 static_assert(testConstexprSpan<long>(), "");62 static_assert(testConstexprSpan<double>(), "");63 static_assert(testConstexprSpan<A>(), "");64 65 testRuntimeSpan<int>();66 testRuntimeSpan<long>();67 testRuntimeSpan<double>();68 testRuntimeSpan<std::string>();69 testRuntimeSpan<A>();70 71 checkCV();72 73 static_assert(std::is_default_constructible_v<std::span<int, std::dynamic_extent>>, "");74 static_assert(std::is_default_constructible_v<std::span<int, 0>>, "");75 static_assert(!std::is_default_constructible_v<std::span<int, 2>>, "");76 77 return 0;78}79