//===----------------------------------------------------------------------===//
//
// 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 OutputIterator, class T,
// class BinaryOperation, class UnaryOperation>
// OutputIterator transform_exclusive_scan(InputIterator first, InputIterator last,
// OutputIterator result, T init,
// BinaryOperation binary_op,
// UnaryOperation unary_op);
#include <numeric>
#include <algorithm>
#include <array>
#include <cassert>
#include <functional>
#include <iterator>
#include "test_macros.h"
#include "test_iterators.h"
struct add_one {
template <typename T>
constexpr auto operator()(T x) const noexcept {
return static_cast<T>(x + 1);
}
};
template <class Iter1, class BOp, class UOp, class T>
TEST_CONSTEXPR_CXX20 void
test(Iter1 first, Iter1 last, BOp bop, UOp uop, T init, const T *rFirst, const T *rLast)
{
assert((rLast - rFirst) <= 5); // or else increase the size of "out"
T out[5];
// Not in place
T *end = std::transform_exclusive_scan(first, last, out, init, bop, uop);
assert(std::equal(out, end, rFirst, rLast));
// In place
std::copy(first, last, out);
end = std::transform_exclusive_scan(out, end, out, init, bop, uop);
assert(std::equal(out, end, rFirst, rLast));
}
template <class Iter>
TEST_CONSTEXPR_CXX20 void
test()
{
int ia[] = { 1, 3, 5, 7, 9 };
const int pResI0[] = { 0, 2, 6, 12, 20 }; // with add_one
const int mResI0[] = { 0, 0, 0, 0, 0 };
const int pResN0[] = { 0, -1, -4, -9, -16 }; // with negate
const int mResN0[] = { 0, 0, 0, 0, 0 };
const int pResI2[] = { 2, 4, 8, 14, 22 }; // with add_one
const int mResI2[] = { 2, 4, 16, 96, 768 };
const int pResN2[] = { 2, 1, -2, -7, -14 }; // with negate
const int mResN2[] = { 2, -2, 6, -30, 210 };
const unsigned sa = sizeof(ia) / sizeof(ia[0]);
static_assert(sa == sizeof(pResI0) / sizeof(pResI0[0])); // just to be sure
static_assert(sa == sizeof(mResI0) / sizeof(mResI0[0])); // just to be sure
static_assert(sa == sizeof(pResN0) / sizeof(pResN0[0])); // just to be sure
static_assert(sa == sizeof(mResN0) / sizeof(mResN0[0])); // just to be sure
static_assert(sa == sizeof(pResI2) / sizeof(pResI2[0])); // just to be sure
static_assert(sa == sizeof(mResI2) / sizeof(mResI2[0])); // just to be sure
static_assert(sa == sizeof(pResN2) / sizeof(pResN2[0])); // just to be sure
static_assert(sa == sizeof(mResN2) / sizeof(mResN2[0])); // just to be sure
for (unsigned int i = 0; i < sa; ++i ) {
test(Iter(ia), Iter(ia + i), std::plus<>(), add_one{}, 0, pResI0, pResI0 + i);
test(Iter(ia), Iter(ia + i), std::multiplies<>(), add_one{}, 0, mResI0, mResI0 + i);
test(Iter(ia), Iter(ia + i), std::plus<>(), std::negate<>(), 0, pResN0, pResN0 + i);
test(Iter(ia), Iter(ia + i), std::multiplies<>(), std::negate<>(), 0, mResN0, mResN0 + i);
test(Iter(ia), Iter(ia + i), std::plus<>(), add_one{}, 2, pResI2, pResI2 + i);
test(Iter(ia), Iter(ia + i), std::multiplies<>(), add_one{}, 2, mResI2, mResI2 + i);
test(Iter(ia), Iter(ia + i), std::plus<>(), std::negate<>(), 2, pResN2, pResN2 + i);
test(Iter(ia), Iter(ia + i), std::multiplies<>(), std::negate<>(), 2, mResN2, mResN2 + i);
}
}
constexpr std::size_t triangle(size_t n) { return n*(n+1)/2; }
// Basic sanity
TEST_CONSTEXPR_CXX20 void
basic_tests()
{
{
std::array<std::size_t, 10> v;
std::fill(v.begin(), v.end(), 3);
std::transform_exclusive_scan(v.begin(), v.end(), v.begin(), std::size_t{50}, std::plus<>(), add_one{});
for (std::size_t i = 0; i < v.size(); ++i)
assert(v[i] == 50 + i * 4);
}
{
std::array<std::size_t, 10> v;
std::iota(v.begin(), v.end(), 0);
std::transform_exclusive_scan(v.begin(), v.end(), v.begin(), std::size_t{30}, std::plus<>(), add_one{});
for (std::size_t i = 0; i < v.size(); ++i)
assert(v[i] == 30 + triangle(i - 1) + i);
}
{
std::array<std::size_t, 10> v;
std::iota(v.begin(), v.end(), 1);
std::transform_exclusive_scan(v.begin(), v.end(), v.begin(), std::size_t{40}, std::plus<>(), add_one{});
for (std::size_t i = 0; i < v.size(); ++i)
assert(v[i] == 40 + triangle(i) + i);
}
{
std::array<std::size_t, 0> v, res;
std::transform_exclusive_scan(v.begin(), v.end(), res.begin(), std::size_t{40}, std::plus<>(), add_one{});
assert(res.empty());
}
// 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));
std::array<std::size_t, 10> res;
std::transform_exclusive_scan(v.begin(), v.end(), res.begin(), std::size_t{1}, std::multiplies<>(), add_one{});
assert(res.size() == 10);
std::size_t j = 1;
assert(res[0] == 1);
for (std::size_t i = 1; i < res.size(); ++i)
{
j *= i + 1;
assert(res[i] == j);
}
}
}
TEST_CONSTEXPR_CXX20 bool
test()
{
basic_tests();
// All the iterator categories
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*>();
test< int*>();
return true;
}
int main(int, char**)
{
test();
#if TEST_STD_VER > 17
static_assert(test());
#endif
return 0;
}
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