//===----------------------------------------------------------------------===//
//
// 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
// constexpr iter_difference_t<I> count() const noexcept;
#include <iterator>
#include "test_macros.h"
#include "test_iterators.h"
struct InputOrOutputArchetype {
using difference_type = int;
int *ptr;
constexpr int operator*() { return *ptr; }
constexpr void operator++(int) { ++ptr; }
constexpr InputOrOutputArchetype& operator++() { ++ptr; return *this; }
};
constexpr bool test() {
int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
{
std::counted_iterator iter(cpp20_input_iterator<int*>{buffer}, 8);
for (int i = 8; i != 0; --i, ++iter)
assert(iter.count() == i);
static_assert(noexcept(iter.count()));
}
{
std::counted_iterator iter(forward_iterator<int*>{buffer}, 8);
for (int i = 8; i != 0; --i, ++iter)
assert(iter.count() == i);
static_assert(noexcept(iter.count()));
}
{
std::counted_iterator iter(contiguous_iterator<int*>{buffer}, 8);
for (int i = 8; i != 0; --i, ++iter)
assert(iter.count() == i);
}
{
std::counted_iterator iter(InputOrOutputArchetype{buffer + 2}, 6);
assert(iter.count() == 6);
}
// Const tests.
{
const std::counted_iterator iter(cpp20_input_iterator<int*>{buffer}, 8);
assert(iter.count() == 8);
}
{
const std::counted_iterator iter(forward_iterator<int*>{buffer + 1}, 7);
assert(iter.count() == 7);
}
{
const std::counted_iterator iter(contiguous_iterator<int*>{buffer + 2}, 6);
assert(iter.count() == 6);
}
{
const std::counted_iterator iter(InputOrOutputArchetype{buffer + 2}, 6);
assert(iter.count() == 6);
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}