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_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
32 test()
33 {
34     typedef std::hash<SV> H;
35     static_assert((std::is_same<typename H::argument_type, SV>::value), "" );
36     static_assert((std::is_same<typename H::result_type, std::size_t>::value), "" );
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()
60 {
61     test<std::string_view>();
62 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
63     test<std::u16string_view>();
64     test<std::u32string_view>();
65 #endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
66     test<std::wstring_view>();
67 }
68