libcxx/test/support/indirectly_readable.h

   1 // -*- C++ -*-
   2 //===----------------------------------------------------------------------===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #ifndef LIBCXX_TEST_SUPPORT_INDIRECTLY_READABLE_H
  11 #define LIBCXX_TEST_SUPPORT_INDIRECTLY_READABLE_H
  12
  13 #include <type_traits>
  14
  15 template <class Token>
  16 struct Common { };
  17
  18 template <class Token>
  19 struct T1 : Common<Token> { };
  20
  21 template <class Token>
  22 struct T2 : Common<Token> { };
  23
  24 template <template <class> class T1Qual, template <class> class T2Qual, class Token>
  25 struct std::basic_common_reference<T1<Token>, T2<Token>, T1Qual, T2Qual> {
  26   using type = Common<Token>;
  27 };
  28 template <template <class> class T2Qual, template <class> class T1Qual, class Token>
  29 struct std::basic_common_reference<T2<Token>, T1<Token>, T2Qual, T1Qual>
  30   : std::basic_common_reference<T1<Token>, T2<Token>, T1Qual, T2Qual>
  31 { };
  32
  33 template <class Token>
  34 struct IndirectlyReadable {
  35   using value_type = T1<Token>;
  36   T2<Token>& operator*() const;
  37 };
  38
  39 #endif // LIBCXX_TEST_SUPPORT_INDIRECTLY_READABLE_H