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 // constexpr outer-iterator(outer-iterator<!Const> i)
12 //   requires Const && convertible_to<iterator_t<View>, iterator_t<Base>>
13 
14 #include <ranges>
15 
16 #include <string_view>
17 #include <type_traits>
18 #include <utility>
19 #include "../types.h"
20 
21 // outer-iterator<Const = true>
22 
23 template <class Iter>
24 concept IsConstOuterIter = requires (Iter i) {
25   { *(*i).begin() } -> std::same_as<const char&>;
26 };
27 static_assert( IsConstOuterIter<OuterIterConst>);
28 
29 static_assert( std::convertible_to<
30     std::ranges::iterator_t<SplitViewDiff>, std::ranges::iterator_t<const SplitViewDiff>>);
31 
32 // outer-iterator<Const = false>
33 
34 template <class Iter>
35 concept IsNonConstOuterIter = requires (Iter i) {
36   { *(*i).begin() } -> std::same_as<char&>;
37 };
38 static_assert( IsNonConstOuterIter<OuterIterNonConst>);
39 
40 static_assert(!std::is_constructible_v<OuterIterNonConst, OuterIterConst>);
41 
test()42 constexpr bool test() {
43   [[maybe_unused]] OuterIterConst i(OuterIterNonConst{});
44 
45   return true;
46 }
47 
main(int,char **)48 int main(int, char**) {
49   test();
50   static_assert(test());
51 
52   return 0;
53 }
54