121 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++11, c++1410 11// <numeric>12 13// Became constexpr in C++2014// 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 28template <class Iter1, class T>29TEST_CONSTEXPR_CXX20 void30test(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 place36 T *end = std::inclusive_scan(first, last, out);37 assert(std::equal(out, end, rFirst, rLast));38 39 // In place40 std::copy(first, last, out);41 end = std::inclusive_scan(out, end, out);42 assert(std::equal(out, end, rFirst, rLast));43}44 45 46template <class Iter>47TEST_CONSTEXPR_CXX20 void48test()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 sure54 55 for (unsigned int i = 0; i < sa; ++i ) {56 test(Iter(ia), Iter(ia + i), pRes, pRes + i);57 }58}59 60constexpr std::size_t triangle(size_t n) { return n*(n+1)/2; }61 62// Basic sanity63TEST_CONSTEXPR_CXX20 void64basic_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 97TEST_CONSTEXPR_CXX20 bool98test()99{100 basic_tests();101 102// All the iterator categories103 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 113int main(int, char**)114{115 test();116#if TEST_STD_VER > 17117 static_assert(test());118#endif119 return 0;120}121