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 // constexpr reference operator[](size_type idx) const; 13 // 14 15 16 #include <span> 17 #include <cassert> 18 #include <string> 19 20 #include "test_macros.h" 21 22 23 template <typename Span> 24 constexpr bool testConstexprSpan(Span sp, size_t idx) 25 { 26 LIBCPP_ASSERT(noexcept(sp[idx])); 27 28 typename Span::reference r1 = sp[idx]; 29 typename Span::reference r2 = *(sp.data() + idx); 30 return r1 == r2; 31 } 32 33 34 template <typename Span> 35 void testRuntimeSpan(Span sp, size_t idx) 36 { 37 LIBCPP_ASSERT(noexcept(sp[idx])); 38 39 typename Span::reference r1 = sp[idx]; 40 typename Span::reference r2 = *(sp.data() + idx); 41 assert(r1 == r2); 42 } 43 44 struct A{}; 45 constexpr int iArr1[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; 46 int iArr2[] = {10, 11, 12, 13, 14, 15, 16, 17, 18, 19}; 47 48 int main(int, char**) 49 { 50 static_assert(testConstexprSpan(std::span<const int>(iArr1, 1), 0), ""); 51 52 static_assert(testConstexprSpan(std::span<const int>(iArr1, 2), 0), ""); 53 static_assert(testConstexprSpan(std::span<const int>(iArr1, 2), 1), ""); 54 55 static_assert(testConstexprSpan(std::span<const int>(iArr1, 3), 0), ""); 56 static_assert(testConstexprSpan(std::span<const int>(iArr1, 3), 1), ""); 57 static_assert(testConstexprSpan(std::span<const int>(iArr1, 3), 2), ""); 58 59 static_assert(testConstexprSpan(std::span<const int>(iArr1, 4), 0), ""); 60 static_assert(testConstexprSpan(std::span<const int>(iArr1, 4), 1), ""); 61 static_assert(testConstexprSpan(std::span<const int>(iArr1, 4), 2), ""); 62 static_assert(testConstexprSpan(std::span<const int>(iArr1, 4), 3), ""); 63 64 65 static_assert(testConstexprSpan(std::span<const int, 1>(iArr1, 1), 0), ""); 66 67 static_assert(testConstexprSpan(std::span<const int, 2>(iArr1, 2), 0), ""); 68 static_assert(testConstexprSpan(std::span<const int, 2>(iArr1, 2), 1), ""); 69 70 static_assert(testConstexprSpan(std::span<const int, 3>(iArr1, 3), 0), ""); 71 static_assert(testConstexprSpan(std::span<const int, 3>(iArr1, 3), 1), ""); 72 static_assert(testConstexprSpan(std::span<const int, 3>(iArr1, 3), 2), ""); 73 74 static_assert(testConstexprSpan(std::span<const int, 4>(iArr1, 4), 0), ""); 75 static_assert(testConstexprSpan(std::span<const int, 4>(iArr1, 4), 1), ""); 76 static_assert(testConstexprSpan(std::span<const int, 4>(iArr1, 4), 2), ""); 77 static_assert(testConstexprSpan(std::span<const int, 4>(iArr1, 4), 3), ""); 78 79 80 testRuntimeSpan(std::span<int>(iArr2, 1), 0); 81 82 testRuntimeSpan(std::span<int>(iArr2, 2), 0); 83 testRuntimeSpan(std::span<int>(iArr2, 2), 1); 84 85 testRuntimeSpan(std::span<int>(iArr2, 3), 0); 86 testRuntimeSpan(std::span<int>(iArr2, 3), 1); 87 testRuntimeSpan(std::span<int>(iArr2, 3), 2); 88 89 testRuntimeSpan(std::span<int>(iArr2, 4), 0); 90 testRuntimeSpan(std::span<int>(iArr2, 4), 1); 91 testRuntimeSpan(std::span<int>(iArr2, 4), 2); 92 testRuntimeSpan(std::span<int>(iArr2, 4), 3); 93 94 95 testRuntimeSpan(std::span<int, 1>(iArr2, 1), 0); 96 97 testRuntimeSpan(std::span<int, 2>(iArr2, 2), 0); 98 testRuntimeSpan(std::span<int, 2>(iArr2, 2), 1); 99 100 testRuntimeSpan(std::span<int, 3>(iArr2, 3), 0); 101 testRuntimeSpan(std::span<int, 3>(iArr2, 3), 1); 102 testRuntimeSpan(std::span<int, 3>(iArr2, 3), 2); 103 104 testRuntimeSpan(std::span<int, 4>(iArr2, 4), 0); 105 testRuntimeSpan(std::span<int, 4>(iArr2, 4), 1); 106 testRuntimeSpan(std::span<int, 4>(iArr2, 4), 2); 107 testRuntimeSpan(std::span<int, 4>(iArr2, 4), 3); 108 109 std::string s; 110 testRuntimeSpan(std::span<std::string> (&s, 1), 0); 111 testRuntimeSpan(std::span<std::string, 1>(&s, 1), 0); 112 113 return 0; 114 } 115