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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
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17
// constexpr decltype(auto) operator*();
// constexpr decltype(auto) operator*() const
// requires dereferenceable<const I>;
#include <iterator>
#include "test_macros.h"
#include "test_iterators.h"
struct InputOrOutputArchetype {
using difference_type = int;
int *ptr;
constexpr int operator*() const { return *ptr; }
constexpr void operator++(int) { ++ptr; }
constexpr InputOrOutputArchetype& operator++() { ++ptr; return *this; }
};
struct NonConstDeref {
using difference_type = int;
int *ptr;
constexpr int operator*() { return *ptr; }
constexpr void operator++(int) { ++ptr; }
constexpr NonConstDeref& operator++() { ++ptr; return *this; }
};
template<class T>
concept IsDereferenceable = requires(T& i) {
*i;
};
constexpr bool test() {
int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
{
static_assert( IsDereferenceable<std::counted_iterator<InputOrOutputArchetype>>);
static_assert( IsDereferenceable<const std::counted_iterator<InputOrOutputArchetype>>);
static_assert( IsDereferenceable<std::counted_iterator<NonConstDeref>>);
static_assert(!IsDereferenceable<const std::counted_iterator<NonConstDeref>>);
}
{
std::counted_iterator iter(cpp20_input_iterator<int*>{buffer}, 8);
for (int i = 1; i < 9; ++i, ++iter)
assert(*iter == i);
}
{
std::counted_iterator iter(forward_iterator<int*>{buffer}, 8);
for (int i = 1; i < 9; ++i, ++iter)
assert(*iter == i);
}
{
std::counted_iterator iter(contiguous_iterator<int*>{buffer}, 8);
for (int i = 1; i < 9; ++i, ++iter)
assert(*iter == i);
}
{
std::counted_iterator iter(InputOrOutputArchetype{buffer}, 8);
for (int i = 1; i < 9; ++i, ++iter)
assert(*iter == i);
}
{
const std::counted_iterator iter(cpp20_input_iterator<int*>{buffer}, 8);
assert(*iter == 1);
}
{
const std::counted_iterator iter(forward_iterator<int*>{buffer + 1}, 7);
assert(*iter == 2);
}
{
const std::counted_iterator iter(contiguous_iterator<int*>{buffer + 2}, 6);
assert(*iter == 3);
}
{
const std::counted_iterator iter(InputOrOutputArchetype{buffer + 2}, 6);
assert(*iter == 3);
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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