1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9// UNSUPPORTED: c++03, c++11, c++14, c++17
10
11// template<class I2, class S2>
12// requires convertible_to<const I2&, I> && convertible_to<const S2&, S>
13// constexpr common_iterator(const common_iterator<I2, S2>& x);
14
15#include <cassert>
16#include <iterator>
17#include <type_traits>
18
19constexpr bool test()
20{
21 struct Base {};
22 struct Derived : Base {};
23
24 using BaseIt = std::common_iterator<Base*, const Base*>;
25 using DerivedIt = std::common_iterator<Derived*, const Derived*>;
26 static_assert(std::is_convertible_v<DerivedIt, BaseIt>); // Derived* to Base*
27 static_assert(!std::is_constructible_v<DerivedIt, BaseIt>); // Base* to Derived*
28
29 Derived a[10] = {};
30 DerivedIt it = DerivedIt(a); // the iterator type
31 BaseIt jt = BaseIt(it);
32 assert(jt == BaseIt(a));
33
34 it = DerivedIt((const Derived*)a); // the sentinel type
35 jt = BaseIt(it);
36 assert(jt == BaseIt(a));
37
38 return true;
39}
40
41int main(int, char**) {
42 test();
43 static_assert(test());
44
45 return 0;
46}
47

source code of libcxx/test/std/iterators/predef.iterators/iterators.common/ctor.converting.pass.cpp