1// Copyright (C) 2016 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3
4#ifndef QSET_H
5#define QSET_H
6
7#include <QtCore/qhash.h>
8#include <QtCore/qcontainertools_impl.h>
9#include <QtCore/qttypetraits.h>
10
11#include <initializer_list>
12#include <iterator>
13
14QT_BEGIN_NAMESPACE
15
16
17template <class T>
18class QSet
19{
20 typedef QHash<T, QHashDummyValue> Hash;
21
22public:
23 inline QSet() noexcept {}
24 inline QSet(std::initializer_list<T> list)
25 : QSet(list.begin(), list.end()) {}
26 template <typename InputIterator, QtPrivate::IfIsInputIterator<InputIterator> = true>
27 inline QSet(InputIterator first, InputIterator last)
28 {
29 QtPrivate::reserveIfForwardIterator(this, first, last);
30 for (; first != last; ++first)
31 insert(*first);
32 }
33
34 // compiler-generated copy/move ctor/assignment operators are fine!
35 // compiler-generated destructor is fine!
36
37 inline void swap(QSet<T> &other) noexcept { q_hash.swap(other.q_hash); }
38
39#ifndef Q_QDOC
40 template <typename U = T>
41 QTypeTraits::compare_eq_result_container<QSet, U> operator==(const QSet<T> &other) const
42 { return q_hash == other.q_hash; }
43 template <typename U = T>
44 QTypeTraits::compare_eq_result_container<QSet, U> operator!=(const QSet<T> &other) const
45 { return q_hash != other.q_hash; }
46#else
47 bool operator==(const QSet &other) const;
48 bool operator!=(const QSet &other) const;
49#endif
50
51 inline qsizetype size() const { return q_hash.size(); }
52
53 inline bool isEmpty() const { return q_hash.isEmpty(); }
54
55 inline qsizetype capacity() const { return q_hash.capacity(); }
56 inline void reserve(qsizetype size);
57 inline void squeeze() { q_hash.squeeze(); }
58
59 inline void detach() { q_hash.detach(); }
60 inline bool isDetached() const { return q_hash.isDetached(); }
61
62 inline void clear() { q_hash.clear(); }
63
64 bool remove(const T &value) { return q_hash.remove(value); }
65
66 template <typename Pred>
67 inline qsizetype removeIf(Pred predicate)
68 {
69 return QtPrivate::qset_erase_if(*this, predicate);
70 }
71
72 inline bool contains(const T &value) const { return q_hash.contains(value); }
73
74 bool contains(const QSet<T> &set) const;
75
76 class const_iterator;
77
78 class iterator
79 {
80 typedef QHash<T, QHashDummyValue> Hash;
81 typename Hash::iterator i;
82 friend class const_iterator;
83 friend class QSet<T>;
84
85 public:
86 typedef std::forward_iterator_tag iterator_category;
87 typedef qptrdiff difference_type;
88 typedef T value_type;
89 typedef const T *pointer;
90 typedef const T &reference;
91
92 inline iterator() {}
93 inline iterator(typename Hash::iterator o) : i(o) {}
94 inline iterator(const iterator &o) : i(o.i) {}
95 inline iterator &operator=(const iterator &o) { i = o.i; return *this; }
96 inline const T &operator*() const { return i.key(); }
97 inline const T *operator->() const { return &i.key(); }
98 inline bool operator==(const iterator &o) const { return i == o.i; }
99 inline bool operator!=(const iterator &o) const { return i != o.i; }
100 inline bool operator==(const const_iterator &o) const
101 { return i == o.i; }
102 inline bool operator!=(const const_iterator &o) const
103 { return i != o.i; }
104 inline iterator &operator++() { ++i; return *this; }
105 inline iterator operator++(int) { iterator r = *this; ++i; return r; }
106 };
107
108 class const_iterator
109 {
110 typedef QHash<T, QHashDummyValue> Hash;
111 typename Hash::const_iterator i;
112 friend class iterator;
113 friend class QSet<T>;
114
115 public:
116 typedef std::forward_iterator_tag iterator_category;
117 typedef qptrdiff difference_type;
118 typedef T value_type;
119 typedef const T *pointer;
120 typedef const T &reference;
121
122 inline const_iterator() {}
123 inline const_iterator(typename Hash::const_iterator o) : i(o) {}
124 inline const_iterator(const const_iterator &o) : i(o.i) {}
125 inline const_iterator(const iterator &o)
126 : i(o.i) {}
127 inline const_iterator &operator=(const const_iterator &o) { i = o.i; return *this; }
128 inline const T &operator*() const { return i.key(); }
129 inline const T *operator->() const { return &i.key(); }
130 inline bool operator==(const const_iterator &o) const { return i == o.i; }
131 inline bool operator!=(const const_iterator &o) const { return i != o.i; }
132 inline const_iterator &operator++() { ++i; return *this; }
133 inline const_iterator operator++(int) { const_iterator r = *this; ++i; return r; }
134 };
135
136 // STL style
137 inline iterator begin() { return q_hash.begin(); }
138 inline const_iterator begin() const noexcept { return q_hash.begin(); }
139 inline const_iterator cbegin() const noexcept { return q_hash.begin(); }
140 inline const_iterator constBegin() const noexcept { return q_hash.constBegin(); }
141 inline iterator end() { return q_hash.end(); }
142 inline const_iterator end() const noexcept { return q_hash.end(); }
143 inline const_iterator cend() const noexcept { return q_hash.end(); }
144 inline const_iterator constEnd() const noexcept { return q_hash.constEnd(); }
145
146 iterator erase(const_iterator i)
147 {
148 Q_ASSERT(i != constEnd());
149 return q_hash.erase(i.i);
150 }
151
152 // more Qt
153 typedef iterator Iterator;
154 typedef const_iterator ConstIterator;
155 inline qsizetype count() const { return q_hash.size(); }
156 inline iterator insert(const T &value)
157 { return q_hash.insert(value, QHashDummyValue()); }
158 inline iterator insert(T &&value)
159 { return q_hash.emplace(std::move(value), QHashDummyValue()); }
160 iterator find(const T &value) { return q_hash.find(value); }
161 const_iterator find(const T &value) const { return q_hash.find(value); }
162 inline const_iterator constFind(const T &value) const { return find(value); }
163 QSet<T> &unite(const QSet<T> &other);
164 QSet<T> &intersect(const QSet<T> &other);
165 bool intersects(const QSet<T> &other) const;
166 QSet<T> &subtract(const QSet<T> &other);
167
168 // STL compatibility
169 typedef T key_type;
170 typedef T value_type;
171 typedef value_type *pointer;
172 typedef const value_type *const_pointer;
173 typedef value_type &reference;
174 typedef const value_type &const_reference;
175 typedef qptrdiff difference_type;
176 typedef qsizetype size_type;
177
178 inline bool empty() const { return isEmpty(); }
179
180 iterator insert(const_iterator, const T &value) { return insert(value); }
181
182 // comfort
183 inline QSet<T> &operator<<(const T &value) { insert(value); return *this; }
184 inline QSet<T> &operator|=(const QSet<T> &other) { unite(other); return *this; }
185 inline QSet<T> &operator|=(const T &value) { insert(value); return *this; }
186 inline QSet<T> &operator&=(const QSet<T> &other) { intersect(other); return *this; }
187 inline QSet<T> &operator&=(const T &value)
188 { QSet<T> result; if (contains(value)) result.insert(value); return (*this = result); }
189 inline QSet<T> &operator+=(const QSet<T> &other) { unite(other); return *this; }
190 inline QSet<T> &operator+=(const T &value) { insert(value); return *this; }
191 inline QSet<T> &operator-=(const QSet<T> &other) { subtract(other); return *this; }
192 inline QSet<T> &operator-=(const T &value) { remove(value); return *this; }
193
194 friend QSet operator|(const QSet &lhs, const QSet &rhs) { return QSet(lhs) |= rhs; }
195 friend QSet operator|(QSet &&lhs, const QSet &rhs) { lhs |= rhs; return std::move(lhs); }
196
197 friend QSet operator&(const QSet &lhs, const QSet &rhs) { return QSet(lhs) &= rhs; }
198 friend QSet operator&(QSet &&lhs, const QSet &rhs) { lhs &= rhs; return std::move(lhs); }
199
200 friend QSet operator+(const QSet &lhs, const QSet &rhs) { return QSet(lhs) += rhs; }
201 friend QSet operator+(QSet &&lhs, const QSet &rhs) { lhs += rhs; return std::move(lhs); }
202
203 friend QSet operator-(const QSet &lhs, const QSet &rhs) { return QSet(lhs) -= rhs; }
204 friend QSet operator-(QSet &&lhs, const QSet &rhs) { lhs -= rhs; return std::move(lhs); }
205
206 QList<T> values() const;
207
208private:
209 static inline QSet intersected_helper(const QSet &lhs, const QSet &rhs);
210
211 Hash q_hash;
212};
213
214template <typename InputIterator,
215 typename ValueType = typename std::iterator_traits<InputIterator>::value_type,
216 QtPrivate::IfIsInputIterator<InputIterator> = true>
217QSet(InputIterator, InputIterator) -> QSet<ValueType>;
218
219template <typename T>
220size_t qHash(const QSet<T> &key, size_t seed = 0)
221noexcept(noexcept(qHashRangeCommutative(key.begin(), key.end(), seed)))
222{
223 return qHashRangeCommutative(key.begin(), key.end(), seed);
224}
225
226// inline function implementations
227
228template <class T>
229Q_INLINE_TEMPLATE void QSet<T>::reserve(qsizetype asize) { q_hash.reserve(asize); }
230
231template <class T>
232Q_INLINE_TEMPLATE QSet<T> &QSet<T>::unite(const QSet<T> &other)
233{
234 if (!q_hash.isSharedWith(other.q_hash)) {
235 for (const T &e : other)
236 insert(e);
237 }
238 return *this;
239}
240
241template <class T>
242Q_INLINE_TEMPLATE QSet<T> &QSet<T>::intersect(const QSet<T> &other)
243{
244 if (q_hash.isSharedWith(other.q_hash)) {
245 // nothing to do
246 } else if (isEmpty() || other.isEmpty()) {
247 // any set intersected with the empty set is the empty set
248 clear();
249 } else if (q_hash.isDetached()) {
250 // do it in-place:
251 removeIf([&other] (const T &e) { return !other.contains(e); });
252 } else {
253 // don't detach *this just to remove some items; create a new set
254 *this = intersected_helper(lhs: *this, rhs: other);
255 }
256 return *this;
257}
258
259template <class T>
260// static
261auto QSet<T>::intersected_helper(const QSet &lhs, const QSet &rhs) -> QSet
262{
263 QSet r;
264
265 const auto l_size = lhs.size();
266 const auto r_size = rhs.size();
267 r.reserve((std::min)(l_size, r_size));
268
269 // Iterate the smaller of the two sets, but always take from lhs, for
270 // consistency with insert():
271
272 if (l_size <= r_size) {
273 // lhs is not larger
274 for (const auto &e : lhs) {
275 if (rhs.contains(e))
276 r.insert(e);
277 }
278 } else {
279 // rhs is smaller
280 for (const auto &e : rhs) {
281 if (const auto it = lhs.find(e); it != lhs.end())
282 r.insert(*it);
283 }
284 }
285
286 return r;
287}
288
289template <class T>
290Q_INLINE_TEMPLATE bool QSet<T>::intersects(const QSet<T> &other) const
291{
292 const bool otherIsBigger = other.size() > size();
293 const QSet &smallestSet = otherIsBigger ? *this : other;
294 const QSet &biggestSet = otherIsBigger ? other : *this;
295 typename QSet::const_iterator i = smallestSet.cbegin();
296 typename QSet::const_iterator e = smallestSet.cend();
297
298 while (i != e) {
299 if (biggestSet.contains(*i))
300 return true;
301 ++i;
302 }
303
304 return false;
305}
306
307template <class T>
308Q_INLINE_TEMPLATE QSet<T> &QSet<T>::subtract(const QSet<T> &other)
309{
310 if (q_hash.isSharedWith(other.q_hash)) {
311 clear();
312 } else {
313 for (const auto &e : other)
314 remove(value: e);
315 }
316 return *this;
317}
318
319template <class T>
320Q_INLINE_TEMPLATE bool QSet<T>::contains(const QSet<T> &other) const
321{
322 typename QSet<T>::const_iterator i = other.constBegin();
323 while (i != other.constEnd()) {
324 if (!contains(*i))
325 return false;
326 ++i;
327 }
328 return true;
329}
330
331template <typename T>
332Q_OUTOFLINE_TEMPLATE QList<T> QSet<T>::values() const
333{
334 QList<T> result;
335 result.reserve(size());
336 typename QSet<T>::const_iterator i = constBegin();
337 while (i != constEnd()) {
338 result.append(*i);
339 ++i;
340 }
341 return result;
342}
343
344Q_DECLARE_SEQUENTIAL_ITERATOR(Set)
345
346#if !defined(QT_NO_JAVA_STYLE_ITERATORS)
347template <typename T>
348class QMutableSetIterator
349{
350 typedef typename QSet<T>::iterator iterator;
351 QSet<T> *c;
352 iterator i, n;
353 inline bool item_exists() const { return c->constEnd() != n; }
354
355public:
356 inline QMutableSetIterator(QSet<T> &container)
357 : c(&container)
358 { i = c->begin(); n = c->end(); }
359 inline QMutableSetIterator &operator=(QSet<T> &container)
360 { c = &container; i = c->begin(); n = c->end(); return *this; }
361 inline void toFront() { i = c->begin(); n = c->end(); }
362 inline void toBack() { i = c->end(); n = i; }
363 inline bool hasNext() const { return c->constEnd() != i; }
364 inline const T &next() { n = i++; return *n; }
365 inline const T &peekNext() const { return *i; }
366 inline void remove()
367 { if (c->constEnd() != n) { i = c->erase(n); n = c->end(); } }
368 inline const T &value() const { Q_ASSERT(item_exists()); return *n; }
369 inline bool findNext(const T &t)
370 { while (c->constEnd() != (n = i)) if (*i++ == t) return true; return false; }
371};
372#endif // QT_NO_JAVA_STYLE_ITERATORS
373
374template <typename T, typename Predicate>
375qsizetype erase_if(QSet<T> &set, Predicate pred)
376{
377 return QtPrivate::qset_erase_if(set, pred);
378}
379
380QT_END_NAMESPACE
381
382#endif // QSET_H
383

source code of qtbase/src/corelib/tools/qset.h