libcxx/test/std/experimental/utilities/propagate_const/propagate_const.nonmembers/hash.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
  10
  11 // <propagate_const>
  12
  13 // template <class T> struct hash<experimental::fundamentals_v2::propagate_const<T>>;
  14
  15 #include <experimental/propagate_const>
  16 #include <cassert>
  17 #include <cstddef>
  18 #include <functional>
  19
  20 #include "test_macros.h"
  21 #include "propagate_const_helpers.h"
  22
  23 using std::experimental::propagate_const;
  24
  25 template <>
  26 struct std::hash<X> {
  27   typedef X first_argument_type;
  28
  29   std::size_t operator()(const first_argument_type&) const { return 99; }
  30 };
  31
  32 int main(int, char**) {
  33
  34   typedef propagate_const<X> P;
  35
  36   P p(1);
  37
  38   auto h = std::hash<P>();
  39
  40   assert(h(p)==99);
  41
  42   return 0;
  43 }