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 // UNSUPPORTED: clang-8 11 12 // Became constexpr in C++20 13 // template<InputIterator InIter, 14 // OutputIterator<auto, const InIter::value_type&> OutIter, 15 // Callable<auto, const InIter::value_type&, InIter::reference> BinaryOperation> 16 // requires HasAssign<InIter::value_type, BinaryOperation::result_type> 17 // && Constructible<InIter::value_type, InIter::reference> 18 // && CopyConstructible<BinaryOperation> 19 // OutIter 20 // partial_sum(InIter first, InIter last, OutIter result, BinaryOperation binary_op); 21 22 #include <numeric> 23 #include <functional> 24 #include <string> 25 #include <cassert> 26 27 #include "test_macros.h" 28 #include "test_iterators.h" 29 30 #if TEST_STD_VER > 17 31 struct rvalue_addable 32 { 33 bool correctOperatorUsed = false; 34 35 // make sure the predicate is passed an rvalue and an lvalue (so check that the first argument was moved) 36 constexpr rvalue_addable operator()(rvalue_addable&& r, rvalue_addable const&) { 37 r.correctOperatorUsed = true; 38 return std::move(r); 39 } 40 }; 41 42 constexpr rvalue_addable operator+(rvalue_addable& lhs, rvalue_addable const&) 43 { 44 lhs.correctOperatorUsed = false; 45 return lhs; 46 } 47 48 constexpr rvalue_addable operator+(rvalue_addable&& lhs, rvalue_addable const&) 49 { 50 lhs.correctOperatorUsed = true; 51 return std::move(lhs); 52 } 53 54 constexpr void 55 test_use_move() 56 { 57 const std::size_t size = 100; 58 rvalue_addable arr[size]; 59 rvalue_addable res1[size]; 60 rvalue_addable res2[size]; 61 std::partial_sum(arr, arr + size, res1); 62 std::partial_sum(arr, arr + size, res2, /*predicate=*/rvalue_addable()); 63 // start at 1 because the first element is not moved 64 for (unsigned i = 1; i < size; ++i) assert(res1[i].correctOperatorUsed); 65 for (unsigned i = 1; i < size; ++i) assert(res2[i].correctOperatorUsed); 66 } 67 #endif // TEST_STD_VER > 17 68 69 // C++20 can use string in constexpr evaluation, but both libc++ and MSVC 70 // don't have the support yet. In these cases omit the constexpr test. 71 // FIXME Remove constexpr string workaround introduced in D90569 72 #if TEST_STD_VER > 17 && \ 73 (!defined(__cpp_lib_constexpr_string) || __cpp_lib_constexpr_string < 201907L) 74 void 75 #else 76 TEST_CONSTEXPR_CXX20 void 77 #endif 78 test_string() 79 { 80 std::string sa[] = {"a", "b", "c"}; 81 std::string sr[] = {"a", "ba", "cb"}; 82 std::string output[3]; 83 std::adjacent_difference(sa, sa + 3, output, std::plus<std::string>()); 84 for (unsigned i = 0; i < 3; ++i) assert(output[i] == sr[i]); 85 } 86 87 template <class InIter, class OutIter> 88 TEST_CONSTEXPR_CXX20 void 89 test() 90 { 91 int ia[] = {1, 2, 3, 4, 5}; 92 int ir[] = {1, -1, -4, -8, -13}; 93 const unsigned s = sizeof(ia) / sizeof(ia[0]); 94 int ib[s] = {0}; 95 OutIter r = std::partial_sum(InIter(ia), InIter(ia+s), OutIter(ib), std::minus<int>()); 96 assert(base(r) == ib + s); 97 for (unsigned i = 0; i < s; ++i) 98 assert(ib[i] == ir[i]); 99 } 100 101 TEST_CONSTEXPR_CXX20 bool 102 test() 103 { 104 test<input_iterator<const int*>, output_iterator<int*> >(); 105 test<input_iterator<const int*>, forward_iterator<int*> >(); 106 test<input_iterator<const int*>, bidirectional_iterator<int*> >(); 107 test<input_iterator<const int*>, random_access_iterator<int*> >(); 108 test<input_iterator<const int*>, int*>(); 109 110 test<forward_iterator<const int*>, output_iterator<int*> >(); 111 test<forward_iterator<const int*>, forward_iterator<int*> >(); 112 test<forward_iterator<const int*>, bidirectional_iterator<int*> >(); 113 test<forward_iterator<const int*>, random_access_iterator<int*> >(); 114 test<forward_iterator<const int*>, int*>(); 115 116 test<bidirectional_iterator<const int*>, output_iterator<int*> >(); 117 test<bidirectional_iterator<const int*>, forward_iterator<int*> >(); 118 test<bidirectional_iterator<const int*>, bidirectional_iterator<int*> >(); 119 test<bidirectional_iterator<const int*>, random_access_iterator<int*> >(); 120 test<bidirectional_iterator<const int*>, int*>(); 121 122 test<random_access_iterator<const int*>, output_iterator<int*> >(); 123 test<random_access_iterator<const int*>, forward_iterator<int*> >(); 124 test<random_access_iterator<const int*>, bidirectional_iterator<int*> >(); 125 test<random_access_iterator<const int*>, random_access_iterator<int*> >(); 126 test<random_access_iterator<const int*>, int*>(); 127 128 test<const int*, output_iterator<int*> >(); 129 test<const int*, forward_iterator<int*> >(); 130 test<const int*, bidirectional_iterator<int*> >(); 131 test<const int*, random_access_iterator<int*> >(); 132 test<const int*, int*>(); 133 134 #if TEST_STD_VER > 17 135 test_use_move(); 136 #endif // TEST_STD_VER > 17 137 // C++20 can use string in constexpr evaluation, but both libc++ and MSVC 138 // don't have the support yet. In these cases omit the constexpr test. 139 // FIXME Remove constexpr string workaround introduced in D90569 140 #if TEST_STD_VER > 17 && \ 141 (!defined(__cpp_lib_constexpr_string) || __cpp_lib_constexpr_string < 201907L) 142 if (!std::is_constant_evaluated()) 143 #endif 144 test_string(); 145 146 return true; 147 } 148 149 int main(int, char**) 150 { 151 test(); 152 #if TEST_STD_VER > 17 153 static_assert(test()); 154 #endif 155 156 return 0; 157 } 158