//===----------------------------------------------------------------------===//
//
// 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 <nothrow-forward-iterator ForwardIterator>
// requires default_initializable<iter_value_t<ForwardIterator>>
// ForwardIterator ranges::uninitialized_value_construct_n(ForwardIterator first,
// iter_difference_t<ForwardIterator> n);
#include <cassert>
#include <memory>
#include <ranges>
#include "../buffer.h"
#include "../counted.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_value_construct_n)>);
struct NotDefaultCtrable {
NotDefaultCtrable() = delete;
};
static_assert(!std::is_invocable_v<decltype(std::ranges::uninitialized_value_construct_n), NotDefaultCtrable*, int>);
int main(int, char**) {
// An empty range -- no default constructors should be invoked.
{
Buffer<Counted, 1> buf;
std::ranges::uninitialized_value_construct_n(buf.begin(), 0);
assert(Counted::current_objects == 0);
assert(Counted::total_objects == 0);
}
// A range containing several objects.
{
constexpr int N = 5;
Buffer<Counted, N> buf;
std::ranges::uninitialized_value_construct_n(buf.begin(), N);
assert(Counted::current_objects == N);
assert(Counted::total_objects == N);
std::destroy(buf.begin(), buf.end());
Counted::reset();
}
// Any existing values should be overwritten by value constructors.
{
constexpr int N = 5;
int buffer[N] = {42, 42, 42, 42, 42};
std::ranges::uninitialized_value_construct_n(buffer, 1);
assert(buffer[0] == 0);
assert(buffer[1] == 42);
std::ranges::uninitialized_value_construct_n(buffer, N);
assert(buffer[0] == 0);
assert(buffer[1] == 0);
assert(buffer[2] == 0);
assert(buffer[3] == 0);
assert(buffer[4] == 0);
}
// An exception is thrown while objects are being created -- the existing objects should stay
// valid.
#ifndef TEST_HAS_NO_EXCEPTIONS
{
constexpr int N = 5;
Buffer<Counted, N> buf;
Counted::throw_on = 3; // When constructing the fourth object (counting from one).
try {
std::ranges::uninitialized_value_construct_n(buf.begin(), N);
} catch (...) {
}
assert(Counted::current_objects == 0);
assert(Counted::total_objects == 3);
std::destroy(buf.begin(), buf.begin() + Counted::total_objects);
Counted::reset();
}
#endif // TEST_HAS_NO_EXCEPTIONS
// Works with const iterators.
{
constexpr int N = 5;
Buffer<Counted, N> buf;
std::ranges::uninitialized_value_construct_n(buf.cbegin(), N);
assert(Counted::current_objects == N);
assert(Counted::total_objects == N);
std::destroy(buf.begin(), buf.end());
Counted::reset();
}
return 0;
}