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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // UNSUPPORTED: c++03, c++11, c++14, c++17 9 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, and 17 // - 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 27 28 void checkCV() 29 { 30 int arr[] = {1,2,3}; 31 const int carr[] = {4,5,6}; 32 volatile int varr[] = {7,8,9}; 33 const volatile int cvarr[] = {1,3,5}; 34 35 // Types the same (dynamic sized) 36 { 37 std::span< int> s1{ arr}; // a span< int> pointing at int. 38 std::span<const int> s2{ carr}; // a span<const int> pointing at const int. 39 std::span< volatile int> s3{ varr}; // a span< volatile int> pointing at volatile int. 40 std::span<const volatile int> s4{cvarr}; // a span<const volatile int> pointing at const volatile int. 41 assert(s1.size() + s2.size() + s3.size() + s4.size() == 12); 42 } 43 44 // Types the same (static sized) 45 { 46 std::span< int,3> s1{ arr}; // a span< int> pointing at int. 47 std::span<const int,3> s2{ carr}; // a span<const int> pointing at const int. 48 std::span< volatile int,3> s3{ varr}; // a span< volatile int> pointing at volatile int. 49 std::span<const volatile int,3> s4{cvarr}; // a span<const volatile int> pointing at const volatile int. 50 assert(s1.size() + s2.size() + s3.size() + s4.size() == 12); 51 } 52 53 54 // types different (dynamic sized) 55 { 56 std::span<const int> s1{ arr}; // a span<const int> pointing at int. 57 std::span< volatile int> s2{ arr}; // a span< volatile int> pointing at int. 58 std::span< volatile int> s3{ arr}; // a span< volatile int> pointing at const int. 59 std::span<const volatile int> s4{ arr}; // a span<const volatile int> pointing at int. 60 std::span<const volatile int> s5{carr}; // a span<const volatile int> pointing at const int. 61 std::span<const volatile int> s6{varr}; // a span<const volatile int> pointing at volatile int. 62 assert(s1.size() + s2.size() + s3.size() + s4.size() + s5.size() + s6.size() == 18); 63 } 64 65 // types different (static sized) 66 { 67 std::span<const int,3> s1{ arr}; // a span<const int> pointing at int. 68 std::span< volatile int,3> s2{ arr}; // a span< volatile int> pointing at int. 69 std::span< volatile int,3> s3{ arr}; // a span< volatile int> pointing at const int. 70 std::span<const volatile int,3> s4{ arr}; // a span<const volatile int> pointing at int. 71 std::span<const volatile int,3> s5{carr}; // a span<const volatile int> pointing at const int. 72 std::span<const volatile int,3> s6{varr}; // a span<const volatile int> pointing at volatile int. 73 assert(s1.size() + s2.size() + s3.size() + s4.size() + s5.size() + s6.size() == 18); 74 } 75 } 76 77 template<class T> 78 constexpr bool testSpan() 79 { 80 T val[2] = {}; 81 82 ASSERT_NOEXCEPT(std::span<T>{val}); 83 ASSERT_NOEXCEPT(std::span<T, 2>{val}); 84 ASSERT_NOEXCEPT(std::span<const T>{val}); 85 ASSERT_NOEXCEPT(std::span<const T, 2>{val}); 86 87 std::span<T> s1 = val; 88 std::span<T, 2> s2 = val; 89 std::span<const T> s3 = val; 90 std::span<const T, 2> s4 = val; 91 assert(s1.data() == val && s1.size() == 2); 92 assert(s2.data() == val && s2.size() == 2); 93 assert(s3.data() == val && s3.size() == 2); 94 assert(s4.data() == val && s4.size() == 2); 95 96 std::span<const int> s5 = {{1,2}}; 97 #if TEST_STD_VER >= 26 98 std::span<const int, 2> s6({1, 2}); 99 #else 100 std::span<const int, 2> s6 = {{1,2}}; 101 #endif 102 assert(s5.size() == 2); // and it dangles 103 assert(s6.size() == 2); // and it dangles 104 105 return true; 106 } 107 108 109 struct A {}; 110 111 int main(int, char**) 112 { 113 testSpan<int>(); 114 testSpan<double>(); 115 testSpan<A>(); 116 testSpan<std::string>(); 117 118 static_assert(testSpan<int>()); 119 static_assert(testSpan<double>()); 120 static_assert(testSpan<A>()); 121 122 checkCV(); 123 124 // Size wrong 125 { 126 static_assert(!std::is_constructible<std::span<int, 2>, int (&)[3]>::value, ""); 127 } 128 129 // Type wrong 130 { 131 static_assert(!std::is_constructible<std::span<float>, int (&)[3]>::value, ""); 132 static_assert(!std::is_constructible<std::span<float, 3>, int (&)[3]>::value, ""); 133 } 134 135 // CV wrong (dynamically sized) 136 { 137 static_assert(!std::is_constructible<std::span<int>, const int (&)[3]>::value, ""); 138 static_assert(!std::is_constructible<std::span<int>, volatile int (&)[3]>::value, ""); 139 static_assert(!std::is_constructible<std::span<int>, const volatile int (&)[3]>::value, ""); 140 141 static_assert(!std::is_constructible<std::span<const int>, volatile int (&)[3]>::value, ""); 142 static_assert(!std::is_constructible<std::span<const int>, const volatile int (&)[3]>::value, ""); 143 144 static_assert(!std::is_constructible<std::span<volatile int>, const int (&)[3]>::value, ""); 145 static_assert(!std::is_constructible<std::span<volatile int>, const volatile int (&)[3]>::value, ""); 146 } 147 148 // CV wrong (statically sized) 149 { 150 static_assert(!std::is_constructible<std::span<int, 3>, const int (&)[3]>::value, ""); 151 static_assert(!std::is_constructible<std::span<int, 3>, volatile int (&)[3]>::value, ""); 152 static_assert(!std::is_constructible<std::span<int, 3>, const volatile int (&)[3]>::value, ""); 153 154 static_assert(!std::is_constructible<std::span<const int, 3>, volatile int (&)[3]>::value, ""); 155 static_assert(!std::is_constructible<std::span<const int, 3>, const volatile int (&)[3]>::value, ""); 156 157 static_assert(!std::is_constructible<std::span<volatile int, 3>, const int (&)[3]>::value, ""); 158 static_assert(!std::is_constructible<std::span<volatile int, 3>, const volatile int (&)[3]>::value, ""); 159 } 160 161 return 0; 162 } 163