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1 | /* A hasher for enums. |
2 | ||
b811d2c2 | 3 | Copyright (C) 2017-2020 Free Software Foundation, Inc. |
e5fa6583 PA |
4 | |
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | #ifndef COMMON_HASH_ENUM_H | |
21 | #define COMMON_HASH_ENUM_H | |
22 | ||
23 | /* A hasher for enums, which was missing in C++11: | |
24 | http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2148 | |
25 | */ | |
26 | ||
27 | namespace gdb { | |
28 | ||
29 | /* Helper struct for hashing enum types. */ | |
30 | template<typename T> | |
31 | struct hash_enum | |
32 | { | |
33 | typedef size_t result_type; | |
34 | typedef T argument_type; | |
35 | ||
36 | size_t operator() (T val) const noexcept | |
37 | { | |
38 | using underlying = typename std::underlying_type<T>::type; | |
39 | return std::hash<underlying> () (static_cast<underlying> (val)); | |
40 | } | |
41 | }; | |
42 | ||
43 | } /* namespace gdb */ | |
44 | ||
45 | #endif /* COMMON_HASH_ENUM_H */ |