libcxx/test/support/test.support/test_poisoned_hash_helper.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
  10
  11 // Test that the header `poisoned_hash_helper.h` doesn't include any
  12 // headers that provide hash<T> specializations. This is required so that the
  13 // 'test_library_hash_specializations_available()' function returns false
  14 // by default, unless a STL header providing hash has already been included.
  15
  16 #include "poisoned_hash_helper.h"
  17
  18 #include "test_macros.h"
  19
  20 template <class T, std::size_t = sizeof(T)>
  21 constexpr bool is_complete_imp(int) { return true; }
  22 template <class> constexpr bool is_complete_imp(long) { return false; }
  23 template <class T> constexpr bool is_complete() { return is_complete_imp<T>(0); }
  24
  25 template <class T> struct has_complete_hash {
  26   enum { value = is_complete<std::hash<T> >() };
  27 };
  28
  29 int main(int, char**) {
  30   static_assert(LibraryHashTypes::assertTrait<has_complete_hash, false>(), "");
  31
  32   return 0;
  33 }