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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
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14
// <numeric>
// Became constexpr in C++20
// template<class InputIterator, class T, class BinaryOperation>
// T reduce(InputIterator first, InputIterator last, T init, BinaryOperation op);
#include <numeric>
#include <cassert>
#include <functional>
#include "test_macros.h"
#include "test_iterators.h"
template <class Iter, class T, class Op>
TEST_CONSTEXPR_CXX20 void
test(Iter first, Iter last, T init, Op op, T x)
{
static_assert( std::is_same_v<T, decltype(std::reduce(first, last, init, op))>, "" );
assert(std::reduce(first, last, init, op) == x);
}
template <class Iter>
TEST_CONSTEXPR_CXX20 void
test()
{
int ia[] = {1, 2, 3, 4, 5, 6};
unsigned sa = sizeof(ia) / sizeof(ia[0]);
test(Iter(ia), Iter(ia), 0, std::plus<>(), 0);
test(Iter(ia), Iter(ia), 1, std::multiplies<>(), 1);
test(Iter(ia), Iter(ia+1), 0, std::plus<>(), 1);
test(Iter(ia), Iter(ia+1), 2, std::multiplies<>(), 2);
test(Iter(ia), Iter(ia+2), 0, std::plus<>(), 3);
test(Iter(ia), Iter(ia+2), 3, std::multiplies<>(), 6);
test(Iter(ia), Iter(ia+sa), 0, std::plus<>(), 21);
test(Iter(ia), Iter(ia+sa), 4, std::multiplies<>(), 2880);
}
template <typename T, typename Init>
TEST_CONSTEXPR_CXX20 void
test_return_type()
{
T *p = nullptr;
static_assert( std::is_same_v<Init, decltype(std::reduce(p, p, Init{}, std::plus<>()))>, "" );
}
TEST_CONSTEXPR_CXX20 bool
test()
{
test_return_type<char, int>();
test_return_type<int, int>();
test_return_type<int, unsigned long>();
test_return_type<float, int>();
test_return_type<short, float>();
test_return_type<double, char>();
test_return_type<char, double>();
test<cpp17_input_iterator<const int*> >();
test<forward_iterator<const int*> >();
test<bidirectional_iterator<const int*> >();
test<random_access_iterator<const int*> >();
test<const int*>();
// Make sure the math is done using the correct type
{
auto v = {1, 2, 3, 4, 5, 6, 7, 8};
unsigned res = std::reduce(v.begin(), v.end(), 1U, std::multiplies<>());
assert(res == 40320); // 8! will not fit into a char
}
return true;
}
int main(int, char**)
{
test();
#if TEST_STD_VER > 17
static_assert(test());
#endif
return 0;
}
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