libcxx/test/std/utilities/template.bitset/bitset.hash/bitset.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 // <functional>
  10
  11 // template <class T>
  12 // struct hash
  13 //     : public unary_function<T, size_t>
  14 // {
  15 //     size_t operator()(T val) const;
  16 // };
  17
  18 #include <bitset>
  19 #include <cassert>
  20 #include <type_traits>
  21
  22 #include "test_macros.h"
  23
  24 template <std::size_t N>
  25 void
  26 test()
  27 {
  28     typedef std::bitset<N> T;
  29     typedef std::hash<T> H;
  30     static_assert((std::is_same<typename H::argument_type, T>::value), "" );
  31     static_assert((std::is_same<typename H::result_type, std::size_t>::value), "" );
  32     ASSERT_NOEXCEPT(H()(T()));
  33
  34     H h;
  35     T bs(static_cast<unsigned long long>(N));
  36     const std::size_t result = h(bs);
  37     LIBCPP_ASSERT(result == N);
  38     ((void)result); // Prevent unused warning
  39 }
  40
  41 int main(int, char**)
  42 {
  43     test<0>();
  44     test<10>();
  45     test<100>();
  46     test<1000>();
  47
  48   return 0;
  49 }