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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
//
//===----------------------------------------------------------------------===//
// <algorithm>
// UNSUPPORTED: c++03, c++11, c++14, c++17
// template<input_iterator I, weakly_incrementable O>
// requires indirectly_copyable<I, O>
// constexpr ranges::copy_n_result<I, O>
// ranges::copy_n(I first, iter_difference_t<I> n, O result);
#include <algorithm>
#include <array>
#include <cassert>
#include <ranges>
#include <vector>
#include "almost_satisfies_types.h"
#include "test_macros.h"
#include "test_iterators.h"
template <class In, class Out = In, class Count = std::size_t>
concept HasCopyNIt = requires(In in, Count count, Out out) { std::ranges::copy_n(in, count, out); };
static_assert(HasCopyNIt<int*>);
static_assert(!HasCopyNIt<InputIteratorNotDerivedFrom>);
static_assert(!HasCopyNIt<InputIteratorNotIndirectlyReadable>);
static_assert(!HasCopyNIt<InputIteratorNotInputOrOutputIterator>);
static_assert(!HasCopyNIt<int*, WeaklyIncrementableNotMovable>);
struct NotIndirectlyCopyable {};
static_assert(!HasCopyNIt<int*, NotIndirectlyCopyable*>);
static_assert(!HasCopyNIt<int*, int*, SentinelForNotSemiregular>);
static_assert(!HasCopyNIt<int*, int*, SentinelForNotWeaklyEqualityComparableWith>);
static_assert(std::is_same_v<std::ranges::copy_result<int, long>, std::ranges::in_out_result<int, long>>);
template <class In, class Out>
constexpr void test_iterators() {
{ // simple test
std::array in{1, 2, 3, 4};
std::array<int, 4> out;
std::same_as<std::ranges::in_out_result<In, Out>> auto ret =
std::ranges::copy_n(In(in.data()), in.size(), Out(out.data()));
assert(in == out);
assert(base(ret.in) == in.data() + in.size());
assert(base(ret.out) == out.data() + out.size());
}
{ // check that an empty range works
std::array<int, 0> in;
std::array<int, 0> out;
auto ret = std::ranges::copy_n(In(in.data()), in.size(), Out(out.data()));
assert(base(ret.in) == in.data());
assert(base(ret.out) == out.data());
}
}
#if TEST_STD_VER >= 23
constexpr bool test_vector_bool(std::size_t N) {
std::vector<bool> in(N, false);
for (std::size_t i = 0; i < N; i += 2)
in[i] = true;
{ // Test copy with aligned bytes
std::vector<bool> out(N);
std::ranges::copy_n(in.begin(), N, out.begin());
assert(in == out);
}
{ // Test copy with unaligned bytes
std::vector<bool> out(N + 8);
std::ranges::copy_n(in.begin(), N, out.begin() + 4);
for (std::size_t i = 0; i < N; ++i)
assert(out[i + 4] == in[i]);
}
return true;
};
#endif
constexpr bool test() {
types::for_each(types::cpp20_input_iterator_list<int*>{}, []<class Out>() {
types::for_each(types::cpp20_input_iterator_list<int*>{}, []<class In>() {
test_iterators<In, Out>();
test_iterators<ProxyIterator<In>, ProxyIterator<Out>>();
});
});
{ // check that every element is copied exactly once
struct CopyOnce {
bool copied = false;
constexpr CopyOnce() = default;
constexpr CopyOnce(const CopyOnce& other) = delete;
constexpr CopyOnce& operator=(const CopyOnce& other) {
assert(!other.copied);
copied = true;
return *this;
}
};
std::array<CopyOnce, 4> in{};
std::array<CopyOnce, 4> out{};
auto ret = std::ranges::copy_n(in.begin(), in.size(), out.begin());
assert(ret.in == in.end());
assert(ret.out == out.end());
assert(std::all_of(out.begin(), out.end(), [](const auto& e) { return e.copied; }));
}
#if TEST_STD_VER >= 23
{ // Test vector<bool>::iterator optimization
assert(test_vector_bool(8));
assert(test_vector_bool(19));
assert(test_vector_bool(32));
assert(test_vector_bool(49));
assert(test_vector_bool(64));
assert(test_vector_bool(199));
assert(test_vector_bool(256));
}
#endif
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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