libcxx/test/std/iterators/iterator.requirements/alg.req.ind.copy/indirectly_copyable.subsumption.compile.pass.cpp

   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 In, class Out>
  12 // concept indirectly_copyable;
  13
  14 #include <iterator>
  15
  16 template<std::indirectly_readable I, class O>
  17 constexpr bool indirectly_copyable_subsumption() {
  18   return false;
  19 }
  20
  21 template<class I, class O>
  22   requires std::indirectly_copyable<I, O>
  23 constexpr bool indirectly_copyable_subsumption() {
  24   return true;
  25 }
  26
  27 static_assert(indirectly_copyable_subsumption<int*, int*>());