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 9 // <numeric> 10 11 // Became constexpr in C++20 12 // template <InputIterator Iter, MoveConstructible T, 13 // Callable<auto, const T&, Iter::reference> BinaryOperation> 14 // requires HasAssign<T, BinaryOperation::result_type> 15 // && CopyConstructible<BinaryOperation> 16 // T 17 // accumulate(Iter first, Iter last, T init, BinaryOperation binary_op); 18 19 #include <numeric> 20 #include <functional> 21 #include <string> 22 #include <cassert> 23 24 #include "test_macros.h" 25 #include "test_iterators.h" 26 27 #if TEST_STD_VER > 17 28 struct rvalue_addable 29 { 30 bool correctOperatorUsed = false; 31 32 // make sure the predicate is passed an rvalue and an lvalue (so check that the first argument was moved) 33 constexpr rvalue_addable operator()(rvalue_addable&& r, rvalue_addable const&) { 34 r.correctOperatorUsed = true; 35 return std::move(r); 36 } 37 }; 38 39 constexpr rvalue_addable operator+(rvalue_addable& lhs, rvalue_addable const&) 40 { 41 lhs.correctOperatorUsed = false; 42 return lhs; 43 } 44 45 constexpr rvalue_addable operator+(rvalue_addable&& lhs, rvalue_addable const&) 46 { 47 lhs.correctOperatorUsed = true; 48 return std::move(lhs); 49 } 50 51 constexpr void 52 test_use_move() 53 { 54 rvalue_addable arr[100]; 55 auto res1 = std::accumulate(arr, arr + 100, rvalue_addable()); 56 auto res2 = std::accumulate(arr, arr + 100, rvalue_addable(), /*predicate=*/rvalue_addable()); 57 assert(res1.correctOperatorUsed); 58 assert(res2.correctOperatorUsed); 59 } 60 #endif // TEST_STD_VER > 17 61 62 // C++20 can use string in constexpr evaluation, but both libc++ and MSVC 63 // don't have the support yet. In these cases omit the constexpr test. 64 // FIXME Remove constexpr string workaround introduced in D90569 65 #if TEST_STD_VER > 17 && \ 66 (!defined(__cpp_lib_constexpr_string) || __cpp_lib_constexpr_string < 201907L) 67 void 68 #else 69 TEST_CONSTEXPR_CXX20 void 70 #endif 71 test_string() 72 { 73 std::string sa[] = {"a", "b", "c"}; 74 assert(std::accumulate(sa, sa + 3, std::string()) == "abc"); 75 assert(std::accumulate(sa, sa + 3, std::string(), std::plus<std::string>()) == "abc"); 76 } 77 78 template <class Iter, class T> 79 TEST_CONSTEXPR_CXX20 void 80 test(Iter first, Iter last, T init, T x) 81 { 82 assert(std::accumulate(first, last, init, std::multiplies<T>()) == x); 83 } 84 85 template <class Iter> 86 TEST_CONSTEXPR_CXX20 void 87 test() 88 { 89 int ia[] = {1, 2, 3, 4, 5, 6}; 90 unsigned sa = sizeof(ia) / sizeof(ia[0]); 91 test(Iter(ia), Iter(ia), 1, 1); 92 test(Iter(ia), Iter(ia), 10, 10); 93 test(Iter(ia), Iter(ia+1), 1, 1); 94 test(Iter(ia), Iter(ia+1), 10, 10); 95 test(Iter(ia), Iter(ia+2), 1, 2); 96 test(Iter(ia), Iter(ia+2), 10, 20); 97 test(Iter(ia), Iter(ia+sa), 1, 720); 98 test(Iter(ia), Iter(ia+sa), 10, 7200); 99 } 100 101 TEST_CONSTEXPR_CXX20 bool 102 test() 103 { 104 test<cpp17_input_iterator<const int*> >(); 105 test<forward_iterator<const int*> >(); 106 test<bidirectional_iterator<const int*> >(); 107 test<random_access_iterator<const int*> >(); 108 test<const int*>(); 109 110 #if TEST_STD_VER > 17 111 test_use_move(); 112 #endif // TEST_STD_VER > 17 113 // C++20 can use string in constexpr evaluation, but both libc++ and MSVC 114 // don't have the support yet. In these cases omit the constexpr test. 115 // FIXME Remove constexpr string workaround introduced in D90569 116 #if TEST_STD_VER > 17 && \ 117 (!defined(__cpp_lib_constexpr_string) || __cpp_lib_constexpr_string < 201907L) 118 if (!std::is_constant_evaluated()) 119 #endif 120 test_string(); 121 122 return true; 123 } 124 125 int main(int, char**) 126 { 127 test(); 128 #if TEST_STD_VER > 17 129 static_assert(test()); 130 #endif 131 return 0; 132 } 133