external/bsd/libc++/dist/libcxx/test/strings/basic.string.hash/strings.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is dual licensed under the MIT and the University of Illinois Open
   6 // Source Licenses. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 // <functional>
  11
  12 // template <class T>
  13 // struct hash
  14 //     : public unary_function<T, size_t>
  15 // {
  16 //     size_t operator()(T val) const;
  17 // };
  18
  19 // Not very portable
  20
  21 #include <string>
  22 #include <cassert>
  23 #include <type_traits>
  24
  25 template <class T>
  26 void
  27 test()
  28 {
  29     typedef std::hash<T> H;
  30     static_assert((std::is_base_of<std::unary_function<T, std::size_t>,
  31                                    H>::value), "");
  32     H h;
  33     std::string g1 = "1234567890";
  34     std::string g2 = "1234567891";
  35     T s1(g1.begin(), g1.end());
  36     T s2(g2.begin(), g2.end());
  37     assert(h(s1) != h(s2));
  38 }
  39
  40 int main()
  41 {
  42     test<std::string>();
  43 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
  44     test<std::u16string>();
  45     test<std::u32string>();
  46 #endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
  47     test<std::wstring>();
  48 }