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 // UNSUPPORTED: libcpp-no-concepts
11 // UNSUPPORTED: gcc-10
12 
13 // template<class I1, class I2>
14 // concept indirectly_swappable;
15 
16 #include <iterator>
17 
18 #include <concepts>
19 
20 template<class I1, class I2>
21   requires std::indirectly_readable<I1> && std::indirectly_readable<I2>
22 constexpr bool indirectly_swappable_subsumption() {
23   return false;
24 }
25 
26 template<class I1, class I2>
27   requires std::indirectly_swappable<I1, I2>
28 constexpr bool indirectly_swappable_subsumption() {
29   return true;
30 }
31 
32 static_assert(indirectly_swappable_subsumption<int*, int*>());
33