//===----------------------------------------------------------------------===//
//
// 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, c++17
// <memory>
//
// template<input_iterator I, nothrow-forward-iterator O, nothrow-sentinel-for<O> S>
// requires constructible_from<iter_value_t<O>, iter_reference_t<I>>
// uninitialized_copy_n_result<I, O> uninitialized_copy_n(I ifirst, iter_difference_t<I> n, O ofirst, S olast); // since C++20
#include <algorithm>
#include <cassert>
#include <iterator>
#include <memory>
#include <ranges>
#include <type_traits>
#include <utility>
#include "../buffer.h"
#include "../counted.h"
#include "../overload_compare_iterator.h"
#include "test_macros.h"
#include "test_iterators.h"
// TODO(varconst): consolidate the ADL checks into a single file.
// Because this is a variable and not a function, it's guaranteed that ADL won't be used. However,
// implementations are allowed to use a different mechanism to achieve this effect, so this check is
// libc++-specific.
LIBCPP_STATIC_ASSERT(std::is_class_v<decltype(std::ranges::uninitialized_copy_n)>);
static_assert(std::is_invocable_v<decltype(std::ranges::uninitialized_copy_n), int*, std::size_t, long*, long*>);
struct NotConvertibleFromInt {};
static_assert(!std::is_invocable_v<decltype(std::ranges::uninitialized_copy_n), int*, std::size_t, NotConvertibleFromInt*,
NotConvertibleFromInt*>);
int main(int, char**) {
// An empty range -- no default constructors should be invoked.
{
Counted in[] = {Counted()};
Buffer<Counted, 1> out;
Counted::reset();
auto result = std::ranges::uninitialized_copy_n(in, 0, out.begin(), out.end());
assert(Counted::current_objects == 0);
assert(Counted::total_objects == 0);
assert(Counted::total_copies == 0);
assert(result.in == in);
assert(result.out == out.begin());
}
Counted::reset();
// A range containing several objects.
{
constexpr int N = 5;
Counted in[N] = {Counted(1), Counted(2), Counted(3), Counted(4), Counted(5)};
Buffer<Counted, N> out;
Counted::reset();
auto result = std::ranges::uninitialized_copy_n(in, N, out.begin(), out.end());
ASSERT_SAME_TYPE(decltype(result), std::ranges::uninitialized_copy_n_result<Counted*, Counted*>);
assert(Counted::current_objects == N);
assert(Counted::total_objects == N);
assert(Counted::total_copies == N);
assert(Counted::total_moves == 0);
assert(std::equal(in, in + N, out.begin(), out.end()));
assert(result.in == in + N);
assert(result.out == out.end());
std::destroy(out.begin(), out.end());
}
Counted::reset();
// An exception is thrown while objects are being created -- the existing objects should stay
// valid. (iterator, sentinel) overload.
#ifndef TEST_HAS_NO_EXCEPTIONS
{
constexpr int M = 3;
constexpr int N = 5;
Counted in[N] = {Counted(1), Counted(2), Counted(3), Counted(4), Counted(5)};
Counted out[N] = {Counted(6), Counted(7), Counted(8), Counted(9), Counted(10)};
Counted::reset();
Counted::throw_on = M; // When constructing out[3].
try {
std::ranges::uninitialized_copy_n(in, N, out, out + N);
assert(false);
} catch (...) {
}
assert(Counted::current_objects == 0);
assert(Counted::total_objects == M);
assert(Counted::total_copies == M);
assert(Counted::total_moves == 0);
assert(out[4].value == 10);
}
Counted::reset();
#endif // TEST_HAS_NO_EXCEPTIONS
// Conversions.
{
constexpr int N = 3;
int in[N] = {1, 2, 3};
Buffer<double, N> out;
std::ranges::uninitialized_copy_n(in, N, out.begin(), out.end());
assert(std::equal(in, in + N, out.begin(), out.end()));
}
// Destination range is shorter than the source range.
{
constexpr int M = 3;
constexpr int N = 5;
Counted in[N] = {Counted(1), Counted(2), Counted(3), Counted(4), Counted(5)};
Buffer<Counted, M> out;
Counted::reset();
auto result = std::ranges::uninitialized_copy_n(in, N, out.begin(), out.end());
assert(Counted::current_objects == M);
assert(Counted::total_objects == M);
assert(Counted::total_copies == M);
assert(Counted::total_moves == 0);
assert(std::equal(in, in + M, out.begin(), out.end()));
assert(result.in == in + M);
assert(result.out == out.end());
}
// Move-only iterators are supported.
{
using MoveOnlyIter = cpp20_input_iterator<const int*>;
static_assert(!std::is_copy_constructible_v<MoveOnlyIter>);
constexpr int N = 3;
int buffer[N] = {1, 2, 3};
MoveOnlyIter in(buffer);
Buffer<int, N> out;
std::ranges::uninitialized_copy_n(std::move(in), N, out.begin(), out.end());
}
// Test with an iterator that overloads operator== and operator!= as the input and output iterators
{
using T = int;
using Iterator = overload_compare_iterator<T*>;
const int N = 5;
// input
{
char pool[sizeof(T) * N] = {0};
T* p = reinterpret_cast<T*>(pool);
T* p_end = reinterpret_cast<T*>(pool) + N;
T array[N] = {1, 2, 3, 4, 5};
std::ranges::uninitialized_copy_n(Iterator(array), N, p, p_end);
for (int i = 0; i != N; ++i) {
assert(array[i] == p[i]);
}
}
// output
{
char pool[sizeof(T) * N] = {0};
T* p = reinterpret_cast<T*>(pool);
T* p_end = reinterpret_cast<T*>(pool) + N;
T array[N] = {1, 2, 3, 4, 5};
std::ranges::uninitialized_copy_n(array, N, Iterator(p), Iterator(p_end));
for (int i = 0; i != N; ++i) {
assert(array[i] == p[i]);
}
}
}
return 0;
}
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