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//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <numeric>
// UNSUPPORTED: c++98, c++03, c++11, c++14
// template <class InputIterator1, class T,
// class BinaryOperation, class UnaryOperation>
// T transform_reduce(InputIterator1 first1, InputIterator1 last1,
// T init, BinaryOperation binary_op, UnaryOperation unary_op);
//
#include <numeric>
#include <cassert>
#include "test_iterators.h"
template <class _Tp = void>
struct identity : std::unary_function<_Tp, _Tp>
{
constexpr const _Tp& operator()(const _Tp& __x) const { return __x;}
};
template <>
struct identity<void>
{
template <class _Tp>
constexpr auto operator()(_Tp&& __x) const
_NOEXCEPT_(noexcept(_VSTD::forward<_Tp>(__x)))
-> decltype (_VSTD::forward<_Tp>(__x))
{ return _VSTD::forward<_Tp>(__x); }
};
template <class _Tp = void>
struct twice
{
constexpr const _Tp operator()(const _Tp& __x) const noexcept { return 2 * __x; }
};
template <>
struct twice<void>
{
template <class _Tp>
constexpr auto operator()(const _Tp& __x) const
_NOEXCEPT_(noexcept(2 * __x))
-> decltype (2 * __x)
{ return 2 * __x; }
};
template <class Iter1, class T, class BOp, class UOp>
void
test(Iter1 first1, Iter1 last1, T init, BOp bOp, UOp uOp, T x)
{
static_assert( std::is_same_v<T,
decltype(std::transform_reduce(first1, last1, init, bOp, uOp))> );
assert(std::transform_reduce(first1, last1, init, bOp, uOp) == x);
}
template <class Iter>
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<>(), identity<>(), 0);
test(Iter(ia), Iter(ia), 1, std::multiplies<>(), identity<>(), 1);
test(Iter(ia), Iter(ia+1), 0, std::multiplies<>(), identity<>(), 0);
test(Iter(ia), Iter(ia+1), 2, std::plus<>(), identity<>(), 3);
test(Iter(ia), Iter(ia+2), 0, std::plus<>(), identity<>(), 3);
test(Iter(ia), Iter(ia+2), 3, std::multiplies<>(), identity<>(), 6);
test(Iter(ia), Iter(ia+sa), 4, std::multiplies<>(), identity<>(), 2880);
test(Iter(ia), Iter(ia+sa), 4, std::plus<>(), identity<>(), 25);
test(Iter(ia), Iter(ia), 0, std::plus<>(), twice<>(), 0);
test(Iter(ia), Iter(ia), 1, std::multiplies<>(), twice<>(), 1);
test(Iter(ia), Iter(ia+1), 0, std::multiplies<>(), twice<>(), 0);
test(Iter(ia), Iter(ia+1), 2, std::plus<>(), twice<>(), 4);
test(Iter(ia), Iter(ia+2), 0, std::plus<>(), twice<>(), 6);
test(Iter(ia), Iter(ia+2), 3, std::multiplies<>(), twice<>(), 24);
test(Iter(ia), Iter(ia+sa), 4, std::multiplies<>(), twice<>(), 184320); // 64 * 2880
test(Iter(ia), Iter(ia+sa), 4, std::plus<>(), twice<>(), 46);
}
template <typename T, typename Init>
void test_return_type()
{
T *p = nullptr;
static_assert( std::is_same_v<Init,
decltype(std::transform_reduce(p, p, Init{}, std::plus<>(), identity<>()))> );
}
int main()
{
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>();
// 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 the math is done using the correct type
{
auto v = {1, 2, 3, 4, 5, 6};
unsigned res = std::transform_reduce(v.begin(), v.end(), 1U, std::multiplies<>(), twice<>());
assert(res == 46080); // 6! * 64 will not fit into a char
}
}
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