3 Copyright (C) 2017-2019 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
20 #ifndef COMMON_HASH_ENUM_H
21 #define COMMON_HASH_ENUM_H
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
29 /* Helper struct for hashing enum types. */
33 typedef size_t result_type;
34 typedef T argument_type;
36 size_t operator() (T val) const noexcept
38 using underlying = typename std::underlying_type<T>::type;
39 return std::hash<underlying> () (static_cast<underlying> (val));
45 #endif /* COMMON_HASH_ENUM_H */