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 <system_error>
22#include <cassert>
23#include <type_traits>
24
25void
26test(int i)
27{
28    typedef std::error_code T;
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    T ec(i, std::system_category());
34    assert(h(ec) == i);
35}
36
37int main()
38{
39    test(0);
40    test(2);
41    test(10);
42}
43