Gazebo Common

API Reference

6.0.0
FlagSet.hh
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1/*
2 * MIT License
3 *
4 * Copyright (c) 2019 Arnaud Kapp (Xaqq), Barry Revzin, Mart Sõmermaa
5 * Copyright (c) 2020 Martin Pecka
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 */
25#ifndef GZ_COMMON_FLAGSET_HH
26#define GZ_COMMON_FLAGSET_HH
27
28// FlagSet is a type-safe class for using enums as flags in C++14 with an
29// underlying std::bitset.
30// See https://github.com/mrts/flag-set-cpp
31// Licence: MIT
32
33#include <bitset>
34#include <iostream>
35#include <cassert>
36#include <string>
37
38namespace gz::common
39{
40
58template<typename T, T LastElement = T::_, bool ExcludeLast = true>
60{
62 public: FlagSet() = default;
63
69 // cppcheck-suppress noExplicitConstructor
70 public: FlagSet(const T& _val)
71 {
72 flags.set(static_cast<UnderlyingType>(_val));
73 }
74
77 public: explicit FlagSet(const std::initializer_list<T>& _list)
78 {
79 for (const auto& val : _list)
80 {
81 flags.set(static_cast<UnderlyingType>(val));
82 }
83 }
84
85 // Binary operations.
86
91 public: FlagSet& operator&=(const T& _val) noexcept
92 {
93 bool tmp = flags.test(static_cast<UnderlyingType>(_val));
94 flags.reset();
95 flags.set(static_cast<UnderlyingType>(_val), tmp);
96 return *this;
97 }
98
102 public: FlagSet& operator&=(const FlagSet& _o) noexcept
103 {
104 flags &= _o.flags;
105 return *this;
106 }
107
111 public: FlagSet& operator|=(const T& _val) noexcept
112 {
113 flags.set(static_cast<UnderlyingType>(_val));
114 return *this;
115 }
116
120 public: FlagSet& operator|=(const FlagSet& _o) noexcept
121 {
122 flags |= _o.flags;
123 return *this;
124 }
125
131 public: FlagSet operator&(const T& _val) const
132 {
133 FlagSet ret(*this);
134 ret &= _val;
135
136 assert(ret.flags.count() <= 1);
137 return ret;
138 }
139
143 public: FlagSet operator&(const FlagSet& _val) const
144 {
145 FlagSet ret(*this);
146 ret.flags &= _val.flags;
147
148 return ret;
149 }
150
155 public: FlagSet operator|(const T& _val) const
156 {
157 FlagSet ret(*this);
158 ret |= _val;
159
160 assert(ret.flags.count() >= 1);
161 return ret;
162 }
163
167 public: FlagSet operator|(const FlagSet& _val) const
168 {
169 FlagSet ret(*this);
170 ret.flags |= _val.flags;
171
172 return ret;
173 }
174
177 public: FlagSet operator~() const
178 {
179 FlagSet cp(*this);
180 cp.flags.flip();
181
182 return cp;
183 }
184
187 public: explicit operator bool() const
188 {
189 return flags.any();
190 }
191
192 // Methods from std::bitset.
193
197 public: bool operator==(const FlagSet& _o) const
198 {
199 return flags == _o.flags;
200 }
201
205 public: bool operator!=(const FlagSet& _o) const
206 {
207 return !(*this == _o);
208 }
209
214 public: std::size_t Size() const
215 {
216 return flags.size();
217 }
218
222 public: std::size_t Count() const
223 {
224 return flags.count();
225 }
226
229 public: FlagSet& Set()
230 {
231 flags.set();
232 return *this;
233 }
234
237 public: FlagSet& Reset()
238 {
239 flags.reset();
240 return *this;
241 }
242
245 public: FlagSet& Flip()
246 {
247 flags.flip();
248 return *this;
249 }
250
255 public: FlagSet& Set(const T& _val, bool _value = true)
256 {
257 flags.set(static_cast<UnderlyingType>(_val), _value);
258 return *this;
259 }
260
264 public: FlagSet& Reset(const T& _val)
265 {
266 flags.reset(static_cast<UnderlyingType>(_val));
267 return *this;
268 }
269
273 public: FlagSet& Flip(const T& _val)
274 {
275 flags.flip(static_cast<UnderlyingType>(_val));
276 return *this;
277 }
278
281 public: bool Any() const
282 {
283 return flags.any();
284 }
285
288 public: bool All() const
289 {
290 return flags.all();
291 }
292
295 public: bool None() const
296 {
297 return flags.none();
298 }
299
301 public: static FlagSet AllSet()
302 {
303 return FlagSet().Set();
304 }
305
307 public: static FlagSet NoneSet()
308 {
309 return FlagSet();
310 }
311
316 public: constexpr bool operator[](const T& _val) const
317 {
318 return flags[static_cast<size_t>(static_cast<UnderlyingType>(_val))];
319 }
320
323 public: std::string String() const
324 {
325 return flags.to_string();
326 }
327
332 public: friend std::ostream& operator<<(std::ostream& _stream,
333 const FlagSet& _self)
334 {
335 return _stream << _self.flags;
336 }
337
340 public: size_t Hash() const
341 {
342 return std::hash<decltype(this->flags)>{}(this->flags);
343 }
344
346 private: using UnderlyingType = std::underlying_type_t<T>;
347
349 public: static constexpr size_t numElements = static_cast<size_t>(
350 static_cast<UnderlyingType>(LastElement) +
351 static_cast<UnderlyingType>(1 - ExcludeLast));
352
354 private: std::bitset<numElements> flags;
355};
356
357template<typename T, typename = void>
361
362template<typename T>
363struct IsEnumThatContainsSentinel<T, decltype(static_cast<void>(T::_))>
364 : std::is_enum<T>
365{
366};
367
368}
369
370// Operator that combines two enumeration values into a FlagSet only if the
371// enumeration contains the sentinel `_`.
372template<typename T>
373std::enable_if_t<
376>
377operator|(const T& _lhs, const T& _rhs)
378{
380 fs |= _lhs;
381 fs |= _rhs;
382
383 return fs;
384}
385
386namespace std
387{
388template<typename T, T LastElement, bool ExcludeLast>
389struct hash<gz::common::FlagSet<T, LastElement, ExcludeLast>>
390{
393 const noexcept
394 {
395 return _s.Hash();
396 }
397};
398}
399
400#endif