rend.pass.cpp (3836B)
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 reverse_iterator rend() const noexcept; 14 // constexpr const_reverse_iterator crend() 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::reverse_iterator e = s. rend(); 27 typename Span::const_reverse_iterator ce = s.crend(); 28 if (s.empty()) 29 { 30 ret = ret && ( e == s.rbegin()); 31 ret = ret && (ce == s.crbegin()); 32 } 33 else 34 { 35 ret = ret && ( e != s.rbegin()); 36 ret = ret && (ce != s.crbegin()); 37 } 38 39 ret = ret && (( e - s.rbegin()) == s.size()); 40 ret = ret && ((ce - s.crbegin()) == s.size()); 41 42 ret = ret && (e == ce); 43 return ret; 44 } 45 46 template <class Span> 47 void testRuntimeSpan(Span s) 48 { 49 typename Span::reverse_iterator e = s. rend(); 50 typename Span::const_reverse_iterator ce = s.crend(); 51 if (s.empty()) 52 { 53 assert( e == s.rbegin()); 54 assert(ce == s.crbegin()); 55 } 56 else 57 { 58 assert( e != s.rbegin()); 59 assert(ce != s.crbegin()); 60 } 61 62 assert(( e - s.rbegin()) == s.size()); 63 assert((ce - s.crbegin()) == s.size()); 64 65 assert(e == ce); 66 } 67 68 69 struct A{}; 70 bool operator==(A, A) {return true;} 71 72 constexpr int iArr1[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; 73 int iArr2[] = {10, 11, 12, 13, 14, 15, 16, 17, 18, 19}; 74 75 76 int main() 77 { 78 static_assert(testConstexprSpan(std::span<int>()), ""); 79 static_assert(testConstexprSpan(std::span<long>()), ""); 80 static_assert(testConstexprSpan(std::span<double>()), ""); 81 static_assert(testConstexprSpan(std::span<A>()), ""); 82 static_assert(testConstexprSpan(std::span<std::string>()), ""); 83 84 static_assert(testConstexprSpan(std::span<int, 0>()), ""); 85 static_assert(testConstexprSpan(std::span<long, 0>()), ""); 86 static_assert(testConstexprSpan(std::span<double, 0>()), ""); 87 static_assert(testConstexprSpan(std::span<A, 0>()), ""); 88 static_assert(testConstexprSpan(std::span<std::string, 0>()), ""); 89 90 static_assert(testConstexprSpan(std::span<const int>(iArr1, 1)), ""); 91 static_assert(testConstexprSpan(std::span<const int>(iArr1, 2)), ""); 92 static_assert(testConstexprSpan(std::span<const int>(iArr1, 3)), ""); 93 static_assert(testConstexprSpan(std::span<const int>(iArr1, 4)), ""); 94 static_assert(testConstexprSpan(std::span<const int>(iArr1, 5)), ""); 95 96 97 testRuntimeSpan(std::span<int> ()); 98 testRuntimeSpan(std::span<long> ()); 99 testRuntimeSpan(std::span<double> ()); 100 testRuntimeSpan(std::span<A> ()); 101 testRuntimeSpan(std::span<std::string>()); 102 103 testRuntimeSpan(std::span<int, 0> ()); 104 testRuntimeSpan(std::span<long, 0> ()); 105 testRuntimeSpan(std::span<double, 0> ()); 106 testRuntimeSpan(std::span<A, 0> ()); 107 testRuntimeSpan(std::span<std::string, 0>()); 108 109 testRuntimeSpan(std::span<int>(iArr2, 1)); 110 testRuntimeSpan(std::span<int>(iArr2, 2)); 111 testRuntimeSpan(std::span<int>(iArr2, 3)); 112 testRuntimeSpan(std::span<int>(iArr2, 4)); 113 testRuntimeSpan(std::span<int>(iArr2, 5)); 114 115 std::string s; 116 testRuntimeSpan(std::span<std::string>(&s, (std::ptrdiff_t) 0)); 117 testRuntimeSpan(std::span<std::string>(&s, 1)); 118 }