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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// <numeric>
// UNSUPPORTED: c++03, c++11, c++14
// UNSUPPORTED: clang-8
// Became constexpr in C++20
// template<class InputIterator, class OutputIterator, class T, class BinaryOperation>
// OutputIterator
// exclusive_scan(InputIterator first, InputIterator last,
// OutputIterator result,
// T init, BinaryOperation binary_op); // C++17
#include <numeric>
#include <algorithm>
#include <array>
#include <cassert>
#include <functional>
#include <iterator>
#include <vector>
#include "test_macros.h"
#include "test_iterators.h"
// FIXME Remove constexpr vector workaround introduced in D90569
#if TEST_STD_VER > 17
#include <span>
#endif
template <class Iter1, class T, class Op, class Iter2>
TEST_CONSTEXPR_CXX20 void
test(Iter1 first, Iter1 last, T init, Op op, Iter2 rFirst, Iter2 rLast)
{
// C++17 doesn't test constexpr so can use a vector.
// C++20 can use vector in constexpr evaluation, but both libc++ and MSVC
// don't have the support yet. In these cases use a std::span for the test.
// FIXME Remove constexpr vector workaround introduced in D90569
size_t size = std::distance(first, last);
#if TEST_STD_VER < 20 || \
(defined(__cpp_lib_constexpr_vector) && __cpp_lib_constexpr_vector >= 201907L)
std::vector<typename std::iterator_traits<Iter1>::value_type> v(size);
#else
assert((size <= 5) && "Increment the size of the array");
typename std::iterator_traits<Iter1>::value_type b[5];
std::span<typename std::iterator_traits<Iter1>::value_type> v{b, size};
#endif
// Not in place
std::exclusive_scan(first, last, v.begin(), init, op);
assert(std::equal(v.begin(), v.end(), rFirst, rLast));
// In place
std::copy(first, last, v.begin());
std::exclusive_scan(v.begin(), v.end(), v.begin(), init, op);
assert(std::equal(v.begin(), v.end(), rFirst, rLast));
}
template <class Iter>
TEST_CONSTEXPR_CXX20 void
test()
{
int ia[] = {1, 3, 5, 7, 9};
const int pRes[] = {0, 1, 4, 9, 16};
const int mRes[] = {1, 1, 3, 15, 105};
const unsigned sa = sizeof(ia) / sizeof(ia[0]);
static_assert(sa == sizeof(pRes) / sizeof(pRes[0])); // just to be sure
static_assert(sa == sizeof(mRes) / sizeof(mRes[0])); // just to be sure
for (unsigned int i = 0; i < sa; ++i ) {
test(Iter(ia), Iter(ia + i), 0, std::plus<>(), pRes, pRes + i);
test(Iter(ia), Iter(ia + i), 1, std::multiplies<>(), mRes, mRes + i);
}
}
TEST_CONSTEXPR_CXX20 bool
test()
{
// All the iterator categories
test<input_iterator <const int*> >();
test<forward_iterator <const int*> >();
test<bidirectional_iterator<const int*> >();
test<random_access_iterator<const int*> >();
test<const int*>();
test< int*>();
// Make sure that the calculations are done using the init typedef
{
std::array<unsigned char, 10> v;
std::iota(v.begin(), v.end(), static_cast<unsigned char>(1));
// C++17 doesn't test constexpr so can use a vector.
// C++20 can use vector in constexpr evaluation, but both libc++ and MSVC
// don't have the support yet. In these cases use a std::span for the test.
// FIXME Remove constexpr vector workaround introduced in D90569
#if TEST_STD_VER < 20 || \
(defined(__cpp_lib_constexpr_vector) && __cpp_lib_constexpr_vector >= 201907L)
std::vector<size_t> res;
std::exclusive_scan(v.begin(), v.end(), std::back_inserter(res), 1, std::multiplies<>());
#else
std::array<size_t, 10> res;
std::exclusive_scan(v.begin(), v.end(), res.begin(), 1, std::multiplies<>());
#endif
assert(res.size() == 10);
size_t j = 1;
assert(res[0] == 1);
for (size_t i = 1; i < v.size(); ++i)
{
j *= i;
assert(res[i] == j);
}
}
return true;
}
int main(int, char**)
{
test();
#if TEST_STD_VER > 17
static_assert(test());
#endif
return 0;
}
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