104 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, class BinaryOperation>15// OutputIterator16// exclusive_scan(InputIterator first, InputIterator last,17// OutputIterator result,18// T init, BinaryOperation binary_op); // C++1719 20#include <numeric>21#include <algorithm>22#include <array>23#include <cassert>24#include <functional>25#include <iterator>26 27#include "test_macros.h"28#include "test_iterators.h"29 30template <class Iter1, class T, class Op>31TEST_CONSTEXPR_CXX20 void32test(Iter1 first, Iter1 last, T init, Op op, const T *rFirst, const T *rLast)33{34 assert((rLast - rFirst) <= 5); // or else increase the size of "out"35 T out[5];36 37 // Not in place38 T *end = std::exclusive_scan(first, last, out, init, op);39 assert(std::equal(out, end, rFirst, rLast));40 41 // In place42 std::copy(first, last, out);43 end = std::exclusive_scan(out, end, out, init, op);44 assert(std::equal(out, end, rFirst, rLast));45}46 47 48template <class Iter>49TEST_CONSTEXPR_CXX20 void50test()51{52 int ia[] = {1, 3, 5, 7, 9};53 const int pRes[] = {0, 1, 4, 9, 16};54 const int mRes[] = {1, 1, 3, 15, 105};55 const unsigned sa = sizeof(ia) / sizeof(ia[0]);56 static_assert(sa == sizeof(pRes) / sizeof(pRes[0])); // just to be sure57 static_assert(sa == sizeof(mRes) / sizeof(mRes[0])); // just to be sure58 59 for (unsigned int i = 0; i < sa; ++i ) {60 test(Iter(ia), Iter(ia + i), 0, std::plus<>(), pRes, pRes + i);61 test(Iter(ia), Iter(ia + i), 1, std::multiplies<>(), mRes, mRes + i);62 }63}64 65TEST_CONSTEXPR_CXX20 bool66test()67{68// All the iterator categories69 test<cpp17_input_iterator <const int*> >();70 test<forward_iterator <const int*> >();71 test<bidirectional_iterator<const int*> >();72 test<random_access_iterator<const int*> >();73 test<const int*>();74 test< int*>();75 76// Make sure that the calculations are done using the init typedef77 {78 std::array<unsigned char, 10> v;79 std::iota(v.begin(), v.end(), static_cast<unsigned char>(1));80 std::array<std::size_t, 10> res;81 std::exclusive_scan(v.begin(), v.end(), res.begin(), 1, std::multiplies<>());82 83 assert(res.size() == 10);84 std::size_t j = 1;85 assert(res[0] == 1);86 for (std::size_t i = 1; i < v.size(); ++i)87 {88 j *= i;89 assert(res[i] == j);90 }91 }92 93 return true;94}95 96int main(int, char**)97{98 test();99#if TEST_STD_VER > 17100 static_assert(test());101#endif102 return 0;103}104