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 InIter, 13 // OutputIterator<auto, const InIter::value_type&> OutIter, 14 // Callable<auto, const InIter::value_type&, InIter::reference> BinaryOperation> 15 // requires HasAssign<InIter::value_type, BinaryOperation::result_type> 16 // && Constructible<InIter::value_type, InIter::reference> 17 // && CopyConstructible<BinaryOperation> 18 // OutIter 19 // partial_sum(InIter first, InIter last, OutIter result, BinaryOperation binary_op); 20 21 #include <numeric> 22 #include <functional> 23 #include <string> 24 #include <cassert> 25 26 #include "test_macros.h" 27 #include "test_iterators.h" 28 29 #if TEST_STD_VER > 17 30 struct rvalue_addable 31 { 32 bool correctOperatorUsed = false; 33 34 // make sure the predicate is passed an rvalue and an lvalue (so check that the first argument was moved) 35 constexpr rvalue_addable operator()(rvalue_addable&& r, rvalue_addable const&) { 36 r.correctOperatorUsed = true; 37 return std::move(r); 38 } 39 }; 40 41 constexpr rvalue_addable operator+(rvalue_addable& lhs, rvalue_addable const&) 42 { 43 lhs.correctOperatorUsed = false; 44 return lhs; 45 } 46 47 constexpr rvalue_addable operator+(rvalue_addable&& lhs, rvalue_addable const&) 48 { 49 lhs.correctOperatorUsed = true; 50 return std::move(lhs); 51 } 52 53 constexpr void 54 test_use_move() 55 { 56 const std::size_t size = 100; 57 rvalue_addable arr[size]; 58 rvalue_addable res1[size]; 59 rvalue_addable res2[size]; 60 std::partial_sum(arr, arr + size, res1); 61 std::partial_sum(arr, arr + size, res2, /*predicate=*/rvalue_addable()); 62 // start at 1 because the first element is not moved 63 for (unsigned i = 1; i < size; ++i) assert(res1[i].correctOperatorUsed); 64 for (unsigned i = 1; i < size; ++i) assert(res2[i].correctOperatorUsed); 65 } 66 #endif // TEST_STD_VER > 17 67 68 // C++20 can use string in constexpr evaluation, but both libc++ and MSVC 69 // don't have the support yet. In these cases omit the constexpr test. 70 // FIXME Remove constexpr string workaround introduced in D90569 71 #if TEST_STD_VER > 17 && \ 72 (!defined(__cpp_lib_constexpr_string) || __cpp_lib_constexpr_string < 201907L) 73 void 74 #else 75 TEST_CONSTEXPR_CXX20 void 76 #endif 77 test_string() 78 { 79 std::string sa[] = {"a", "b", "c"}; 80 std::string sr[] = {"a", "ba", "cb"}; 81 std::string output[3]; 82 std::adjacent_difference(sa, sa + 3, output, std::plus<std::string>()); 83 for (unsigned i = 0; i < 3; ++i) assert(output[i] == sr[i]); 84 } 85 86 template <class InIter, class OutIter> 87 TEST_CONSTEXPR_CXX20 void 88 test() 89 { 90 int ia[] = {1, 2, 3, 4, 5}; 91 int ir[] = {1, -1, -4, -8, -13}; 92 const unsigned s = sizeof(ia) / sizeof(ia[0]); 93 int ib[s] = {0}; 94 OutIter r = std::partial_sum(InIter(ia), InIter(ia+s), OutIter(ib), std::minus<int>()); 95 assert(base(r) == ib + s); 96 for (unsigned i = 0; i < s; ++i) 97 assert(ib[i] == ir[i]); 98 } 99 100 TEST_CONSTEXPR_CXX20 bool 101 test() 102 { 103 test<cpp17_input_iterator<const int*>, cpp17_output_iterator<int*> >(); 104 test<cpp17_input_iterator<const int*>, forward_iterator<int*> >(); 105 test<cpp17_input_iterator<const int*>, bidirectional_iterator<int*> >(); 106 test<cpp17_input_iterator<const int*>, random_access_iterator<int*> >(); 107 test<cpp17_input_iterator<const int*>, int*>(); 108 109 test<forward_iterator<const int*>, cpp17_output_iterator<int*> >(); 110 test<forward_iterator<const int*>, forward_iterator<int*> >(); 111 test<forward_iterator<const int*>, bidirectional_iterator<int*> >(); 112 test<forward_iterator<const int*>, random_access_iterator<int*> >(); 113 test<forward_iterator<const int*>, int*>(); 114 115 test<bidirectional_iterator<const int*>, cpp17_output_iterator<int*> >(); 116 test<bidirectional_iterator<const int*>, forward_iterator<int*> >(); 117 test<bidirectional_iterator<const int*>, bidirectional_iterator<int*> >(); 118 test<bidirectional_iterator<const int*>, random_access_iterator<int*> >(); 119 test<bidirectional_iterator<const int*>, int*>(); 120 121 test<random_access_iterator<const int*>, cpp17_output_iterator<int*> >(); 122 test<random_access_iterator<const int*>, forward_iterator<int*> >(); 123 test<random_access_iterator<const int*>, bidirectional_iterator<int*> >(); 124 test<random_access_iterator<const int*>, random_access_iterator<int*> >(); 125 test<random_access_iterator<const int*>, int*>(); 126 127 test<const int*, cpp17_output_iterator<int*> >(); 128 test<const int*, forward_iterator<int*> >(); 129 test<const int*, bidirectional_iterator<int*> >(); 130 test<const int*, random_access_iterator<int*> >(); 131 test<const int*, int*>(); 132 133 #if TEST_STD_VER > 17 134 test_use_move(); 135 #endif // TEST_STD_VER > 17 136 // C++20 can use string in constexpr evaluation, but both libc++ and MSVC 137 // don't have the support yet. In these cases omit the constexpr test. 138 // FIXME Remove constexpr string workaround introduced in D90569 139 #if TEST_STD_VER > 17 && \ 140 (!defined(__cpp_lib_constexpr_string) || __cpp_lib_constexpr_string < 201907L) 141 if (!std::is_constant_evaluated()) 142 #endif 143 test_string(); 144 145 return true; 146 } 147 148 int main(int, char**) 149 { 150 test(); 151 #if TEST_STD_VER > 17 152 static_assert(test()); 153 #endif 154 155 return 0; 156 } 157