libcxx/test/std/strings/string.view/string.view.hash/string_view.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: !stdlib=libc++ && (c++03 || c++11 || c++14)
  10
  11 // <functional>
  12
  13 // template <class T>
  14 // struct hash
  15 // {
  16 //     size_t operator()(T val) const;
  17 // };
  18
  19 // Not very portable
  20
  21 #include <string_view>
  22 #include <string>
  23 #include <cassert>
  24 #include <type_traits>
  25
  26 #include "test_macros.h"
  27
  28 using std::string_view;
  29
  30 template <class SV>
  31 void test() {
  32   typedef std::hash<SV> H;
  33 #if TEST_STD_VER <= 14
  34   static_assert((std::is_same<typename H::argument_type, SV>::value), "");
  35   static_assert((std::is_same<typename H::result_type, std::size_t>::value), "");
  36 #endif
  37
  38   typedef typename SV::value_type char_type;
  39   typedef std::basic_string<char_type> String;
  40   typedef std::hash<String> SH;
  41   ASSERT_NOEXCEPT(H()(SV()));
  42
  43   char_type g1[10];
  44   char_type g2[10];
  45   for (int i = 0; i < 10; ++i)
  46     g1[i] = g2[9 - i] = static_cast<char_type>('0' + i);
  47   H h;
  48   SH sh;
  49   SV s1(g1, 10);
  50   String ss1(s1);
  51   SV s2(g2, 10);
  52   String ss2(s2);
  53   assert(h(s1) == h(s1));
  54   assert(h(s1) != h(s2));
  55   assert(sh(ss1) == h(s1));
  56   assert(sh(ss2) == h(s2));
  57 }
  58
  59 int main(int, char**) {
  60   test<std::string_view>();
  61 #ifndef TEST_HAS_NO_CHAR8_T
  62   test<std::u8string_view>();
  63 #endif
  64   test<std::u16string_view>();
  65   test<std::u32string_view>();
  66 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  67   test<std::wstring_view>();
  68 #endif
  69
  70   return 0;
  71 }