1/****************************************************************************
2**
3** Copyright (C) 2017 Klarälvdalens Datakonsult AB, a KDAB Group company, [email protected], author Marc Mutz <[email protected]>
4** Copyright (C) 2019 Mail.ru Group.
5** Contact: http://www.qt.io/licensing/
6**
7** This file is part of the QtCore module of the Qt Toolkit.
8**
9** $QT_BEGIN_LICENSE:LGPL$
10** Commercial License Usage
11** Licensees holding valid commercial Qt licenses may use this file in
12** accordance with the commercial license agreement provided with the
13** Software or, alternatively, in accordance with the terms contained in
14** a written agreement between you and The Qt Company. For licensing terms
15** and conditions see https://www.qt.io/terms-conditions. For further
16** information use the contact form at https://www.qt.io/contact-us.
17**
18** GNU Lesser General Public License Usage
19** Alternatively, this file may be used under the terms of the GNU Lesser
20** General Public License version 3 as published by the Free Software
21** Foundation and appearing in the file LICENSE.LGPL3 included in the
22** packaging of this file. Please review the following information to
23** ensure the GNU Lesser General Public License version 3 requirements
24** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
25**
26** GNU General Public License Usage
27** Alternatively, this file may be used under the terms of the GNU
28** General Public License version 2.0 or (at your option) the GNU General
29** Public license version 3 or any later version approved by the KDE Free
30** Qt Foundation. The licenses are as published by the Free Software
31** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
32** included in the packaging of this file. Please review the following
33** information to ensure the GNU General Public License requirements will
34** be met: https://www.gnu.org/licenses/gpl-2.0.html and
35** https://www.gnu.org/licenses/gpl-3.0.html.
36**
37** $QT_END_LICENSE$
38**
39****************************************************************************/
40#ifndef QSTRINGVIEW_H
41#define QSTRINGVIEW_H
42
43#ifndef QT_STRINGVIEW_LEVEL
44# define QT_STRINGVIEW_LEVEL 1
45#endif
46
47#include <QtCore/qchar.h>
48#include <QtCore/qbytearray.h>
49#include <QtCore/qstringliteral.h>
50#include <QtCore/qstringalgorithms.h>
51
52#include <string>
53
54QT_BEGIN_NAMESPACE
55
56class QString;
57class QStringRef;
58class QRegularExpression;
59
60namespace QtPrivate {
61template <typename Char>
62struct IsCompatibleCharTypeHelper
63 : std::integral_constant<bool,
64 std::is_same<Char, QChar>::value ||
65 std::is_same<Char, ushort>::value ||
66 std::is_same<Char, char16_t>::value ||
67 (std::is_same<Char, wchar_t>::value && sizeof(wchar_t) == sizeof(QChar))> {};
68template <typename Char>
69struct IsCompatibleCharType
70 : IsCompatibleCharTypeHelper<typename std::remove_cv<typename std::remove_reference<Char>::type>::type> {};
71
72template <typename Array>
73struct IsCompatibleArrayHelper : std::false_type {};
74template <typename Char, size_t N>
75struct IsCompatibleArrayHelper<Char[N]>
76 : IsCompatibleCharType<Char> {};
77template <typename Array>
78struct IsCompatibleArray
79 : IsCompatibleArrayHelper<typename std::remove_cv<typename std::remove_reference<Array>::type>::type> {};
80
81template <typename Pointer>
82struct IsCompatiblePointerHelper : std::false_type {};
83template <typename Char>
84struct IsCompatiblePointerHelper<Char*>
85 : IsCompatibleCharType<Char> {};
86template <typename Pointer>
87struct IsCompatiblePointer
88 : IsCompatiblePointerHelper<typename std::remove_cv<typename std::remove_reference<Pointer>::type>::type> {};
89
90template <typename T>
91struct IsCompatibleStdBasicStringHelper : std::false_type {};
92template <typename Char, typename...Args>
93struct IsCompatibleStdBasicStringHelper<std::basic_string<Char, Args...> >
94 : IsCompatibleCharType<Char> {};
95
96template <typename T>
97struct IsCompatibleStdBasicString
98 : IsCompatibleStdBasicStringHelper<
99 typename std::remove_cv<typename std::remove_reference<T>::type>::type
100 > {};
101
102} // namespace QtPrivate
103
104class QStringView
105{
106public:
107 typedef char16_t storage_type;
108 typedef const QChar value_type;
109 typedef std::ptrdiff_t difference_type;
110 typedef qsizetype size_type;
111 typedef value_type &reference;
112 typedef value_type &const_reference;
113 typedef value_type *pointer;
114 typedef value_type *const_pointer;
115
116 typedef pointer iterator;
117 typedef const_pointer const_iterator;
118 typedef std::reverse_iterator<iterator> reverse_iterator;
119 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
120
121private:
122 template <typename Char>
123 using if_compatible_char = typename std::enable_if<QtPrivate::IsCompatibleCharType<Char>::value, bool>::type;
124
125 template <typename Array>
126 using if_compatible_array = typename std::enable_if<QtPrivate::IsCompatibleArray<Array>::value, bool>::type;
127
128 template <typename Pointer>
129 using if_compatible_pointer = typename std::enable_if<QtPrivate::IsCompatiblePointer<Pointer>::value, bool>::type;
130
131 template <typename T>
132 using if_compatible_string = typename std::enable_if<QtPrivate::IsCompatibleStdBasicString<T>::value, bool>::type;
133
134 template <typename T>
135 using if_compatible_qstring_like = typename std::enable_if<std::is_same<T, QString>::value || std::is_same<T, QStringRef>::value, bool>::type;
136
137 template <typename Char, size_t N>
138 static Q_DECL_CONSTEXPR qsizetype lengthHelperArray(const Char (&)[N]) noexcept
139 {
140 return qsizetype(N - 1);
141 }
142
143 template <typename Char>
144 static Q_DECL_RELAXED_CONSTEXPR qsizetype lengthHelperPointer(const Char *str) noexcept
145 {
146#if defined(Q_CC_GNU) && !defined(Q_CC_CLANG) && !defined(Q_CC_INTEL)
147 if (__builtin_constant_p(*str)) {
148 qsizetype result = 0;
149 while (*str++)
150 ++result;
151 return result;
152 }
153#endif
154 return QtPrivate::qustrlen(str: reinterpret_cast<const ushort *>(str));
155 }
156 static qsizetype lengthHelperPointer(const QChar *str) noexcept
157 {
158 return QtPrivate::qustrlen(str: reinterpret_cast<const ushort *>(str));
159 }
160
161 template <typename Char>
162 static const storage_type *castHelper(const Char *str) noexcept
163 { return reinterpret_cast<const storage_type*>(str); }
164 static Q_DECL_CONSTEXPR const storage_type *castHelper(const storage_type *str) noexcept
165 { return str; }
166
167public:
168 Q_DECL_CONSTEXPR QStringView() noexcept
169 : m_size(0), m_data(nullptr) {}
170 Q_DECL_CONSTEXPR QStringView(std::nullptr_t) noexcept
171 : QStringView() {}
172
173 template <typename Char, if_compatible_char<Char> = true>
174 Q_DECL_CONSTEXPR QStringView(const Char *str, qsizetype len)
175 : m_size((Q_ASSERT(len >= 0), Q_ASSERT(str || !len), len)),
176 m_data(castHelper(str)) {}
177
178 template <typename Char, if_compatible_char<Char> = true>
179 Q_DECL_CONSTEXPR QStringView(const Char *f, const Char *l)
180 : QStringView(f, l - f) {}
181
182#ifdef Q_CLANG_QDOC
183 template <typename Char, size_t N>
184 Q_DECL_CONSTEXPR QStringView(const Char (&array)[N]) noexcept;
185
186 template <typename Char>
187 Q_DECL_CONSTEXPR QStringView(const Char *str) noexcept;
188#else
189#if QT_DEPRECATED_SINCE(5, 14)
190 template <typename Array, if_compatible_array<Array> = true>
191 QT_DEPRECATED_VERSION_X_5_14(R"(Use u"~~~" or QStringView(u"~~~") instead of QStringViewLiteral("~~~"))")
192 Q_DECL_CONSTEXPR QStringView(const Array &str, QtPrivate::Deprecated_t) noexcept
193 : QStringView(str, lengthHelperArray(str)) {}
194#endif // QT_DEPRECATED_SINCE
195
196 template <typename Array, if_compatible_array<Array> = true>
197 Q_DECL_CONSTEXPR QStringView(const Array &str) noexcept
198 : QStringView(str, lengthHelperArray(str)) {}
199
200 template <typename Pointer, if_compatible_pointer<Pointer> = true>
201 Q_DECL_CONSTEXPR QStringView(const Pointer &str) noexcept
202 : QStringView(str, str ? lengthHelperPointer(str) : 0) {}
203#endif
204
205#ifdef Q_CLANG_QDOC
206 QStringView(const QString &str) noexcept;
207 QStringView(const QStringRef &str) noexcept;
208#else
209 template <typename String, if_compatible_qstring_like<String> = true>
210 QStringView(const String &str) noexcept
211 : QStringView(str.isNull() ? nullptr : str.data(), qsizetype(str.size())) {}
212#endif
213
214 template <typename StdBasicString, if_compatible_string<StdBasicString> = true>
215 Q_DECL_CONSTEXPR QStringView(const StdBasicString &str) noexcept
216 : QStringView(str.data(), qsizetype(str.size())) {}
217
218 Q_REQUIRED_RESULT inline QString toString() const; // defined in qstring.h
219
220 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR qsizetype size() const noexcept { return m_size; }
221 Q_REQUIRED_RESULT const_pointer data() const noexcept { return reinterpret_cast<const_pointer>(m_data); }
222 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR const storage_type *utf16() const noexcept { return m_data; }
223
224 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QChar operator[](qsizetype n) const
225 { return Q_ASSERT(n >= 0), Q_ASSERT(n < size()), QChar(m_data[n]); }
226
227 //
228 // QString API
229 //
230
231 template <typename...Args>
232 Q_REQUIRED_RESULT inline QString arg(Args &&...args) const; // defined in qstring.h
233
234 Q_REQUIRED_RESULT QByteArray toLatin1() const { return QtPrivate::convertToLatin1(str: *this); }
235 Q_REQUIRED_RESULT QByteArray toUtf8() const { return QtPrivate::convertToUtf8(str: *this); }
236 Q_REQUIRED_RESULT QByteArray toLocal8Bit() const { return QtPrivate::convertToLocal8Bit(str: *this); }
237 Q_REQUIRED_RESULT inline QVector<uint> toUcs4() const; // defined in qvector.h
238
239 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QChar at(qsizetype n) const { return (*this)[n]; }
240
241 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QStringView mid(qsizetype pos) const
242 {
243 return QStringView(m_data + qBound(min: qsizetype(0), val: pos, max: m_size), m_size - qBound(min: qsizetype(0), val: pos, max: m_size));
244 }
245 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QStringView mid(qsizetype pos, qsizetype n) const
246 {
247 return QStringView(m_data + qBound(min: qsizetype(0), val: pos, max: m_size),
248 n == -1 ? m_size - pos : qBound(min: qsizetype(0), val: pos + n, max: m_size) - qBound(min: qsizetype(0), val: pos, max: m_size));
249 }
250 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QStringView left(qsizetype n) const
251 {
252 return QStringView(m_data, (size_t(n) > size_t(m_size) ? m_size : n));
253 }
254 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QStringView right(qsizetype n) const
255 {
256 return QStringView(m_data + m_size - (size_t(n) > size_t(m_size) ? m_size : n), (size_t(n) > size_t(m_size) ? m_size : n));
257 }
258 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QStringView chopped(qsizetype n) const
259 { return Q_ASSERT(n >= 0), Q_ASSERT(n <= size()), QStringView(m_data, m_size - n); }
260
261 Q_DECL_RELAXED_CONSTEXPR void truncate(qsizetype n)
262 { Q_ASSERT(n >= 0); Q_ASSERT(n <= size()); m_size = n; }
263 Q_DECL_RELAXED_CONSTEXPR void chop(qsizetype n)
264 { Q_ASSERT(n >= 0); Q_ASSERT(n <= size()); m_size -= n; }
265
266 Q_REQUIRED_RESULT QStringView trimmed() const noexcept { return QtPrivate::trimmed(s: *this); }
267
268 Q_REQUIRED_RESULT int compare(QStringView other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
269 { return QtPrivate::compareStrings(lhs: *this, rhs: other, cs); }
270 Q_REQUIRED_RESULT inline int compare(QLatin1String other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
271 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR int compare(QChar c) const noexcept
272 { return size() >= 1 ? compare_single_char_helper(diff: *utf16() - c.unicode()) : -1; }
273 Q_REQUIRED_RESULT int compare(QChar c, Qt::CaseSensitivity cs) const noexcept
274 { return QtPrivate::compareStrings(lhs: *this, rhs: QStringView(&c, 1), cs); }
275
276 Q_REQUIRED_RESULT bool startsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
277 { return QtPrivate::startsWith(haystack: *this, needle: s, cs); }
278 Q_REQUIRED_RESULT inline bool startsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
279 Q_REQUIRED_RESULT bool startsWith(QChar c) const noexcept
280 { return !empty() && front() == c; }
281 Q_REQUIRED_RESULT bool startsWith(QChar c, Qt::CaseSensitivity cs) const noexcept
282 { return QtPrivate::startsWith(haystack: *this, needle: QStringView(&c, 1), cs); }
283
284 Q_REQUIRED_RESULT bool endsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
285 { return QtPrivate::endsWith(haystack: *this, needle: s, cs); }
286 Q_REQUIRED_RESULT inline bool endsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
287 Q_REQUIRED_RESULT bool endsWith(QChar c) const noexcept
288 { return !empty() && back() == c; }
289 Q_REQUIRED_RESULT bool endsWith(QChar c, Qt::CaseSensitivity cs) const noexcept
290 { return QtPrivate::endsWith(haystack: *this, needle: QStringView(&c, 1), cs); }
291
292 Q_REQUIRED_RESULT qsizetype indexOf(QChar c, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
293 { return QtPrivate::findString(haystack: *this, from, needle: QStringView(&c, 1), cs); }
294 Q_REQUIRED_RESULT qsizetype indexOf(QStringView s, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
295 { return QtPrivate::findString(haystack: *this, from, needle: s, cs); }
296 Q_REQUIRED_RESULT inline qsizetype indexOf(QLatin1String s, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
297
298 Q_REQUIRED_RESULT bool contains(QChar c, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
299 { return indexOf(s: QStringView(&c, 1), from: 0, cs) != qsizetype(-1); }
300 Q_REQUIRED_RESULT bool contains(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
301 { return indexOf(s, from: 0, cs) != qsizetype(-1); }
302 Q_REQUIRED_RESULT inline bool contains(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
303
304 Q_REQUIRED_RESULT inline qsizetype count(QChar c, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
305 Q_REQUIRED_RESULT inline qsizetype count(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
306
307 Q_REQUIRED_RESULT qsizetype lastIndexOf(QChar c, qsizetype from = -1, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
308 { return QtPrivate::lastIndexOf(haystack: *this, from, needle: QStringView(&c, 1), cs); }
309 Q_REQUIRED_RESULT qsizetype lastIndexOf(QStringView s, qsizetype from = -1, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
310 { return QtPrivate::lastIndexOf(haystack: *this, from, needle: s, cs); }
311 Q_REQUIRED_RESULT inline qsizetype lastIndexOf(QLatin1String s, qsizetype from = -1, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
312
313 Q_REQUIRED_RESULT bool isRightToLeft() const noexcept
314 { return QtPrivate::isRightToLeft(string: *this); }
315 Q_REQUIRED_RESULT bool isValidUtf16() const noexcept
316 { return QtPrivate::isValidUtf16(s: *this); }
317
318 Q_REQUIRED_RESULT inline short toShort(bool *ok = nullptr, int base = 10) const;
319 Q_REQUIRED_RESULT inline ushort toUShort(bool *ok = nullptr, int base = 10) const;
320 Q_REQUIRED_RESULT inline int toInt(bool *ok = nullptr, int base = 10) const;
321 Q_REQUIRED_RESULT inline uint toUInt(bool *ok = nullptr, int base = 10) const;
322 Q_REQUIRED_RESULT inline long toLong(bool *ok = nullptr, int base = 10) const;
323 Q_REQUIRED_RESULT inline ulong toULong(bool *ok = nullptr, int base = 10) const;
324 Q_REQUIRED_RESULT inline qlonglong toLongLong(bool *ok = nullptr, int base = 10) const;
325 Q_REQUIRED_RESULT inline qulonglong toULongLong(bool *ok = nullptr, int base = 10) const;
326 Q_REQUIRED_RESULT inline float toFloat(bool *ok = nullptr) const;
327 Q_REQUIRED_RESULT inline double toDouble(bool *ok = nullptr) const;
328
329 Q_REQUIRED_RESULT inline int toWCharArray(wchar_t *array) const; // defined in qstring.h
330
331 Q_REQUIRED_RESULT inline
332 QList<QStringView> split(QStringView sep,
333 Qt::SplitBehavior behavior = Qt::KeepEmptyParts,
334 Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
335 Q_REQUIRED_RESULT inline
336 QList<QStringView> split(QChar sep, Qt::SplitBehavior behavior = Qt::KeepEmptyParts,
337 Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
338
339#if QT_CONFIG(regularexpression)
340 Q_REQUIRED_RESULT inline
341 QList<QStringView> split(const QRegularExpression &sep, Qt::SplitBehavior behavior = Qt::KeepEmptyParts) const;
342#endif
343
344 //
345 // STL compatibility API:
346 //
347 Q_REQUIRED_RESULT const_iterator begin() const noexcept { return data(); }
348 Q_REQUIRED_RESULT const_iterator end() const noexcept { return data() + size(); }
349 Q_REQUIRED_RESULT const_iterator cbegin() const noexcept { return begin(); }
350 Q_REQUIRED_RESULT const_iterator cend() const noexcept { return end(); }
351 Q_REQUIRED_RESULT const_reverse_iterator rbegin() const noexcept { return const_reverse_iterator(end()); }
352 Q_REQUIRED_RESULT const_reverse_iterator rend() const noexcept { return const_reverse_iterator(begin()); }
353 Q_REQUIRED_RESULT const_reverse_iterator crbegin() const noexcept { return rbegin(); }
354 Q_REQUIRED_RESULT const_reverse_iterator crend() const noexcept { return rend(); }
355
356 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR bool empty() const noexcept { return size() == 0; }
357 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QChar front() const { return Q_ASSERT(!empty()), QChar(m_data[0]); }
358 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QChar back() const { return Q_ASSERT(!empty()), QChar(m_data[m_size - 1]); }
359
360 //
361 // Qt compatibility API:
362 //
363 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR bool isNull() const noexcept { return !m_data; }
364 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR bool isEmpty() const noexcept { return empty(); }
365 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR int length() const /* not nothrow! */
366 { return Q_ASSERT(int(size()) == size()), int(size()); }
367 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QChar first() const { return front(); }
368 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QChar last() const { return back(); }
369private:
370 qsizetype m_size;
371 const storage_type *m_data;
372
373 Q_DECL_CONSTEXPR int compare_single_char_helper(int diff) const noexcept
374 { return diff ? diff : size() > 1 ? 1 : 0; }
375};
376Q_DECLARE_TYPEINFO(QStringView, Q_PRIMITIVE_TYPE);
377
378template <typename QStringLike, typename std::enable_if<
379 std::is_same<QStringLike, QString>::value || std::is_same<QStringLike, QStringRef>::value,
380 bool>::type = true>
381inline QStringView qToStringViewIgnoringNull(const QStringLike &s) noexcept
382{ return QStringView(s.data(), s.size()); }
383
384QT_END_NAMESPACE
385
386#endif /* QSTRINGVIEW_H */
387

source code of qtbase/src/corelib/text/qstringview.h