160 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// template<size_t N>13// constexpr span(element_type (&arr)[N]) noexcept;14//15// Remarks: These constructors shall not participate in overload resolution unless:16// - extent == dynamic_extent || N == extent is true, and17// - remove_pointer_t<decltype(data(arr))>(*)[] is convertible to ElementType(*)[].18//19 20#include <cassert>21#include <span>22#include <string>23#include <type_traits>24 25#include "test_macros.h"26 27void checkCV() {28 int arr[] = {1, 2, 3};29 const int carr[] = {4, 5, 6};30 volatile int varr[] = {7, 8, 9};31 const volatile int cvarr[] = {1, 3, 5};32 33 // Types the same (dynamic sized)34 {35 std::span< int> s1{arr}; // a span< int> pointing at int.36 std::span<const int> s2{carr}; // a span<const int> pointing at const int.37 std::span< volatile int> s3{varr}; // a span< volatile int> pointing at volatile int.38 std::span<const volatile int> s4{cvarr}; // a span<const volatile int> pointing at const volatile int.39 assert(s1.size() + s2.size() + s3.size() + s4.size() == 12);40 }41 42 // Types the same (static sized)43 {44 std::span< int, 3> s1{arr}; // a span< int> pointing at int.45 std::span<const int, 3> s2{carr}; // a span<const int> pointing at const int.46 std::span< volatile int, 3> s3{varr}; // a span< volatile int> pointing at volatile int.47 std::span<const volatile int, 3> s4{cvarr}; // a span<const volatile int> pointing at const volatile int.48 assert(s1.size() + s2.size() + s3.size() + s4.size() == 12);49 }50 51 // types different (dynamic sized)52 {53 std::span<const int> s1{arr}; // a span<const int> pointing at int.54 std::span< volatile int> s2{arr}; // a span< volatile int> pointing at int.55 std::span< volatile int> s3{arr}; // a span< volatile int> pointing at const int.56 std::span<const volatile int> s4{arr}; // a span<const volatile int> pointing at int.57 std::span<const volatile int> s5{carr}; // a span<const volatile int> pointing at const int.58 std::span<const volatile int> s6{varr}; // a span<const volatile int> pointing at volatile int.59 assert(s1.size() + s2.size() + s3.size() + s4.size() + s5.size() + s6.size() == 18);60 }61 62 // types different (static sized)63 {64 std::span<const int, 3> s1{arr}; // a span<const int> pointing at int.65 std::span< volatile int, 3> s2{arr}; // a span< volatile int> pointing at int.66 std::span< volatile int, 3> s3{arr}; // a span< volatile int> pointing at const int.67 std::span<const volatile int, 3> s4{arr}; // a span<const volatile int> pointing at int.68 std::span<const volatile int, 3> s5{carr}; // a span<const volatile int> pointing at const int.69 std::span<const volatile int, 3> s6{varr}; // a span<const volatile int> pointing at volatile int.70 assert(s1.size() + s2.size() + s3.size() + s4.size() + s5.size() + s6.size() == 18);71 }72}73 74template <class T>75constexpr bool testSpan() {76 T val[2] = {};77 78 ASSERT_NOEXCEPT(std::span<T>{val});79 ASSERT_NOEXCEPT(std::span<T, 2>{val});80 ASSERT_NOEXCEPT(std::span<const T>{val});81 ASSERT_NOEXCEPT(std::span<const T, 2>{val});82 83 std::span<T> s1 = val;84 std::span<T, 2> s2 = val;85 std::span<const T> s3 = val;86 std::span<const T, 2> s4 = val;87 assert(s1.data() == val && s1.size() == 2);88 assert(s2.data() == val && s2.size() == 2);89 assert(s3.data() == val && s3.size() == 2);90 assert(s4.data() == val && s4.size() == 2);91 92 TEST_DIAGNOSTIC_PUSH93 TEST_CLANG_DIAGNOSTIC_IGNORED("-Wdangling")94 std::span<const int> s5 = {{1, 2}};95#if TEST_STD_VER >= 2696 std::span<const int, 2> s6({1, 2});97#else98 std::span<const int, 2> s6 = {{1, 2}};99#endif100 assert(s5.size() == 2); // and it dangles101 assert(s6.size() == 2); // and it dangles102 TEST_DIAGNOSTIC_POP103 104 return true;105}106 107struct A {};108 109int main(int, char**) {110 testSpan<int>();111 testSpan<double>();112 testSpan<A>();113 testSpan<std::string>();114 115 static_assert(testSpan<int>());116 static_assert(testSpan<double>());117 static_assert(testSpan<A>());118 119 checkCV();120 121 // Size wrong122 {123 static_assert(!std::is_constructible<std::span<int, 2>, int(&)[3]>::value, "");124 }125 126 // Type wrong127 {128 static_assert(!std::is_constructible<std::span<float>, int(&)[3]>::value, "");129 static_assert(!std::is_constructible<std::span<float, 3>, int(&)[3]>::value, "");130 }131 132 // CV wrong (dynamically sized)133 {134 static_assert(!std::is_constructible<std::span<int>, const int(&)[3]>::value, "");135 static_assert(!std::is_constructible<std::span<int>, volatile int(&)[3]>::value, "");136 static_assert(!std::is_constructible<std::span<int>, const volatile int(&)[3]>::value, "");137 138 static_assert(!std::is_constructible<std::span<const int>, volatile int(&)[3]>::value, "");139 static_assert(!std::is_constructible<std::span<const int>, const volatile int(&)[3]>::value, "");140 141 static_assert(!std::is_constructible<std::span<volatile int>, const int(&)[3]>::value, "");142 static_assert(!std::is_constructible<std::span<volatile int>, const volatile int(&)[3]>::value, "");143 }144 145 // CV wrong (statically sized)146 {147 static_assert(!std::is_constructible<std::span<int, 3>, const int(&)[3]>::value, "");148 static_assert(!std::is_constructible<std::span<int, 3>, volatile int(&)[3]>::value, "");149 static_assert(!std::is_constructible<std::span<int, 3>, const volatile int(&)[3]>::value, "");150 151 static_assert(!std::is_constructible<std::span<const int, 3>, volatile int(&)[3]>::value, "");152 static_assert(!std::is_constructible<std::span<const int, 3>, const volatile int(&)[3]>::value, "");153 154 static_assert(!std::is_constructible<std::span<volatile int, 3>, const int(&)[3]>::value, "");155 static_assert(!std::is_constructible<std::span<volatile int, 3>, const volatile int(&)[3]>::value, "");156 }157 158 return 0;159}160