libcxx/test/std/strings/basic.string.hash/strings.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 // {
  14 //     size_t operator()(T val) const;
  15 // };
  16
  17 // Not very portable
  18
  19 #include <string>
  20 #include <cassert>
  21 #include <type_traits>
  22
  23 #include "test_macros.h"
  24
  25 template <class T>
  26 void test() {
  27   typedef std::hash<T> H;
  28 #if TEST_STD_VER <= 14
  29   static_assert((std::is_same<typename H::argument_type, T>::value), "");
  30   static_assert((std::is_same<typename H::result_type, std::size_t>::value), "");
  31 #endif
  32   ASSERT_NOEXCEPT(H()(T()));
  33
  34   H h;
  35   std::string g1 = "1234567890";
  36   std::string g2 = "1234567891";
  37   T s1(g1.begin(), g1.end());
  38   T s2(g2.begin(), g2.end());
  39   assert(h(s1) != h(s2));
  40 }
  41
  42 int main(int, char**) {
  43   test<std::string>();
  44 #ifndef TEST_HAS_NO_CHAR8_T
  45   test<std::u8string>();
  46 #endif
  47   test<std::u16string>();
  48   test<std::u32string>();
  49 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  50   test<std::wstring>();
  51 #endif
  52
  53   return 0;
  54 }