1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17 10 11 // <span> 12 13 // constexpr iterator begin() const noexcept; 14 // constexpr const_iterator cbegin() const noexcept; 15 16 #include <span> 17 #include <cassert> 18 #include <string> 19 20 #include "test_macros.h" 21 22 template <class Span> 23 constexpr bool testConstexprSpan(Span s) 24 { 25 bool ret = true; 26 typename Span::iterator b = s. begin(); 27 typename Span::const_iterator cb = s.cbegin(); 28 29 if (s.empty()) 30 { 31 ret = ret && ( b == s.end()); 32 ret = ret && (cb == s.cend()); 33 } 34 else 35 { 36 ret = ret && ( *b == s[0]); 37 ret = ret && ( &*b == &s[0]); 38 ret = ret && ( *cb == s[0]); 39 ret = ret && (&*cb == &s[0]); 40 } 41 ret = ret && (b == cb); 42 return ret; 43 } 44 45 46 template <class Span> 47 void testRuntimeSpan(Span s) 48 { 49 typename Span::iterator b = s. begin(); 50 typename Span::const_iterator cb = s.cbegin(); 51 52 if (s.empty()) 53 { 54 assert( b == s.end()); 55 assert(cb == s.cend()); 56 } 57 else 58 { 59 assert( *b == s[0]); 60 assert( &*b == &s[0]); 61 assert( *cb == s[0]); 62 assert(&*cb == &s[0]); 63 } 64 assert(b == cb); 65 } 66 67 struct A{}; 68 bool operator==(A, A) {return true;} 69 70 constexpr int iArr1[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; 71 int iArr2[] = {10, 11, 12, 13, 14, 15, 16, 17, 18, 19}; 72 73 74 int main() 75 { 76 static_assert(testConstexprSpan(std::span<int>()), ""); 77 static_assert(testConstexprSpan(std::span<long>()), ""); 78 static_assert(testConstexprSpan(std::span<double>()), ""); 79 static_assert(testConstexprSpan(std::span<A>()), ""); 80 static_assert(testConstexprSpan(std::span<std::string>()), ""); 81 82 static_assert(testConstexprSpan(std::span<int, 0>()), ""); 83 static_assert(testConstexprSpan(std::span<long, 0>()), ""); 84 static_assert(testConstexprSpan(std::span<double, 0>()), ""); 85 static_assert(testConstexprSpan(std::span<A, 0>()), ""); 86 static_assert(testConstexprSpan(std::span<std::string, 0>()), ""); 87 88 static_assert(testConstexprSpan(std::span<const int>(iArr1, 1)), ""); 89 static_assert(testConstexprSpan(std::span<const int>(iArr1, 2)), ""); 90 static_assert(testConstexprSpan(std::span<const int>(iArr1, 3)), ""); 91 static_assert(testConstexprSpan(std::span<const int>(iArr1, 4)), ""); 92 static_assert(testConstexprSpan(std::span<const int>(iArr1, 5)), ""); 93 94 95 testRuntimeSpan(std::span<int> ()); 96 testRuntimeSpan(std::span<long> ()); 97 testRuntimeSpan(std::span<double> ()); 98 testRuntimeSpan(std::span<A> ()); 99 testRuntimeSpan(std::span<std::string>()); 100 101 testRuntimeSpan(std::span<int, 0> ()); 102 testRuntimeSpan(std::span<long, 0> ()); 103 testRuntimeSpan(std::span<double, 0> ()); 104 testRuntimeSpan(std::span<A, 0> ()); 105 testRuntimeSpan(std::span<std::string, 0>()); 106 107 testRuntimeSpan(std::span<int>(iArr2, 1)); 108 testRuntimeSpan(std::span<int>(iArr2, 2)); 109 testRuntimeSpan(std::span<int>(iArr2, 3)); 110 testRuntimeSpan(std::span<int>(iArr2, 4)); 111 testRuntimeSpan(std::span<int>(iArr2, 5)); 112 113 std::string s; 114 testRuntimeSpan(std::span<std::string>(&s, (std::ptrdiff_t) 0)); 115 testRuntimeSpan(std::span<std::string>(&s, 1)); 116 } 117
