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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
// template<class I2, class S2>
// requires convertible_to<const I2&, I> && convertible_to<const S2&, S>
// constexpr common_iterator(const common_iterator<I2, S2>& x);
#include <cassert>
#include <iterator>
#include <type_traits>
constexpr bool test()
{
struct Base {};
struct Derived : Base {};
using BaseIt = std::common_iterator<Base*, const Base*>;
using DerivedIt = std::common_iterator<Derived*, const Derived*>;
static_assert(std::is_convertible_v<DerivedIt, BaseIt>); // Derived* to Base*
static_assert(!std::is_constructible_v<DerivedIt, BaseIt>); // Base* to Derived*
Derived a[10] = {};
DerivedIt it = DerivedIt(a); // the iterator type
BaseIt jt = BaseIt(it);
assert(jt == BaseIt(a));
it = DerivedIt((const Derived*)a); // the sentinel type
jt = BaseIt(it);
assert(jt == BaseIt(a));
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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