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 #include <system_error>
20 #include <cassert>
21 #include <type_traits>
22 
23 #include "test_macros.h"
24 
25 void
test(int i)26 test(int i)
27 {
28     typedef std::error_code T;
29     typedef std::hash<T> H;
30     static_assert((std::is_same<H::argument_type, T>::value), "" );
31     static_assert((std::is_same<H::result_type, std::size_t>::value), "" );
32     ASSERT_NOEXCEPT(H()(T()));
33     H h;
34     T ec(i, std::system_category());
35     const std::size_t result = h(ec);
36     LIBCPP_ASSERT(result == static_cast<std::size_t>(i));
37     ((void)result); // Prevent unused warning
38 }
39 
main()40 int main()
41 {
42     test(0);
43     test(2);
44     test(10);
45 }
46