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 // UNSUPPORTED: c++03, c++11, c++14 10 11 // <numeric> 12 13 // Became constexpr in C++20 14 // template<class InputIterator, class OutputIterator, class T> 15 // OutputIterator inclusive_scan(InputIterator first, InputIterator last, 16 // OutputIterator result, T init); 17 // 18 19 #include <algorithm> 20 #include <array> 21 #include <cassert> 22 #include <cstddef> 23 #include <numeric> 24 25 #include "test_macros.h" 26 #include "test_iterators.h" 27 28 template <class Iter1, class T> 29 TEST_CONSTEXPR_CXX20 void 30 test(Iter1 first, Iter1 last, const T *rFirst, const T *rLast) 31 { 32 assert((rLast - rFirst) <= 5); // or else increase the size of "out" 33 T out[5]; 34 35 // Not in place 36 T *end = std::inclusive_scan(first, last, out); 37 assert(std::equal(out, end, rFirst, rLast)); 38 39 // In place 40 std::copy(first, last, out); 41 end = std::inclusive_scan(out, end, out); 42 assert(std::equal(out, end, rFirst, rLast)); 43 } 44 45 46 template <class Iter> 47 TEST_CONSTEXPR_CXX20 void 48 test() 49 { 50 int ia[] = {1, 3, 5, 7, 9}; 51 const int pRes[] = {1, 4, 9, 16, 25}; 52 const unsigned sa = sizeof(ia) / sizeof(ia[0]); 53 static_assert(sa == sizeof(pRes) / sizeof(pRes[0])); // just to be sure 54 55 for (unsigned int i = 0; i < sa; ++i ) { 56 test(Iter(ia), Iter(ia + i), pRes, pRes + i); 57 } 58 } 59 60 constexpr std::size_t triangle(size_t n) { return n*(n+1)/2; } 61 62 // Basic sanity 63 TEST_CONSTEXPR_CXX20 void 64 basic_tests() 65 { 66 { 67 std::array<std::size_t, 10> v; 68 std::fill(v.begin(), v.end(), 3); 69 std::inclusive_scan(v.begin(), v.end(), v.begin()); 70 for (std::size_t i = 0; i < v.size(); ++i) 71 assert(v[i] == (i+1) * 3); 72 } 73 74 { 75 std::array<std::size_t, 10> v; 76 std::iota(v.begin(), v.end(), 0); 77 std::inclusive_scan(v.begin(), v.end(), v.begin()); 78 for (std::size_t i = 0; i < v.size(); ++i) 79 assert(v[i] == triangle(i)); 80 } 81 82 { 83 std::array<std::size_t, 10> v; 84 std::iota(v.begin(), v.end(), 1); 85 std::inclusive_scan(v.begin(), v.end(), v.begin()); 86 for (std::size_t i = 0; i < v.size(); ++i) 87 assert(v[i] == triangle(i + 1)); 88 } 89 90 { 91 std::array<std::size_t, 0> v, res; 92 std::inclusive_scan(v.begin(), v.end(), res.begin()); 93 assert(res.empty()); 94 } 95 } 96 97 TEST_CONSTEXPR_CXX20 bool 98 test() 99 { 100 basic_tests(); 101 102 // All the iterator categories 103 test<cpp17_input_iterator <const int*> >(); 104 test<forward_iterator <const int*> >(); 105 test<bidirectional_iterator<const int*> >(); 106 test<random_access_iterator<const int*> >(); 107 test<const int*>(); 108 test< int*>(); 109 110 return true; 111 } 112 113 int main(int, char**) 114 { 115 test(); 116 #if TEST_STD_VER > 17 117 static_assert(test()); 118 #endif 119 return 0; 120 } 121