xref: /netbsd-src/external/gpl3/gdb.old/dist/gdbsupport/hash_enum.h (revision 6881a4007f077b54e5f51159c52b9b25f57deb0d)
17d62b00eSchristos /* A hasher for enums.
27d62b00eSchristos 
3*6881a400Schristos    Copyright (C) 2017-2023 Free Software Foundation, Inc.
47d62b00eSchristos 
57d62b00eSchristos    This file is part of GDB.
67d62b00eSchristos 
77d62b00eSchristos    This program is free software; you can redistribute it and/or modify
87d62b00eSchristos    it under the terms of the GNU General Public License as published by
97d62b00eSchristos    the Free Software Foundation; either version 3 of the License, or
107d62b00eSchristos    (at your option) any later version.
117d62b00eSchristos 
127d62b00eSchristos    This program is distributed in the hope that it will be useful,
137d62b00eSchristos    but WITHOUT ANY WARRANTY; without even the implied warranty of
147d62b00eSchristos    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
157d62b00eSchristos    GNU General Public License for more details.
167d62b00eSchristos 
177d62b00eSchristos    You should have received a copy of the GNU General Public License
187d62b00eSchristos    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
197d62b00eSchristos 
207d62b00eSchristos #ifndef COMMON_HASH_ENUM_H
217d62b00eSchristos #define COMMON_HASH_ENUM_H
227d62b00eSchristos 
237d62b00eSchristos /* A hasher for enums, which was missing in C++11:
247d62b00eSchristos     http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2148
257d62b00eSchristos */
267d62b00eSchristos 
277d62b00eSchristos namespace gdb {
287d62b00eSchristos 
297d62b00eSchristos /* Helper struct for hashing enum types.  */
307d62b00eSchristos template<typename T>
317d62b00eSchristos struct hash_enum
327d62b00eSchristos {
337d62b00eSchristos   typedef size_t result_type;
347d62b00eSchristos   typedef T argument_type;
357d62b00eSchristos 
367d62b00eSchristos   size_t operator() (T val) const noexcept
377d62b00eSchristos   {
387d62b00eSchristos     using underlying = typename std::underlying_type<T>::type;
397d62b00eSchristos     return std::hash<underlying> () (static_cast<underlying> (val));
407d62b00eSchristos   }
417d62b00eSchristos };
427d62b00eSchristos 
437d62b00eSchristos } /* namespace gdb */
447d62b00eSchristos 
457d62b00eSchristos #endif /* COMMON_HASH_ENUM_H */
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