| 1 | /* A hasher for enums. |
| 2 | |
| 3 | Copyright (C) 2017-2020 Free Software Foundation, Inc. |
| 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 */ |