include/QtCore/qlatin1stringview.h

0001 // Copyright (C) 2020 The Qt Company Ltd.
0002 // Copyright (C) 2019 Intel Corporation.
0003 // Copyright (C) 2019 Mail.ru Group.
0004 // Copyright (C) 2020 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Marc Mutz <marc.mutz@kdab.com>
0005 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
0006
0007 #ifndef QLATIN1STRINGVIEW_H
0008 #define QLATIN1STRINGVIEW_H
0009
0010 #include <QtCore/qchar.h>
0011 #include <QtCore/qcompare.h>
0012 #include <QtCore/qcontainerfwd.h>
0013 #include <QtCore/qnamespace.h>
0014 #include <QtCore/qtversionchecks.h>
0015 #include <QtCore/qstringfwd.h>
0016 #include <QtCore/qstringview.h>
0017
0018 #if 0
0019 // Workaround for generating forward headers
0020 #pragma qt_class(QLatin1String)
0021 #pragma qt_class(QLatin1StringView)
0022 #endif
0023
0024 QT_BEGIN_NAMESPACE
0025
0026 class QString;
0027
0028 #ifdef Q_L1S_VIEW_IS_PRIMARY
0029 class QLatin1StringView
0030 #else
0031 class QLatin1String
0032 #endif
0033 {
0034 public:
0035 #ifdef Q_L1S_VIEW_IS_PRIMARY
0036     constexpr QLatin1StringView() noexcept {}
0037     constexpr QLatin1StringView(std::nullptr_t) noexcept : QLatin1StringView() {}
0038     constexpr explicit QLatin1StringView(const char *s) noexcept
0039         : QLatin1StringView(s, s ? qsizetype(QtPrivate::lengthHelperPointer(s)) : 0) {}
0040     constexpr QLatin1StringView(const char *f, const char *l)
0041         : QLatin1StringView(f, qsizetype(l - f)) {}
0042     constexpr QLatin1StringView(const char *s, qsizetype sz) noexcept : m_data(s), m_size(sz) {}
0043     explicit QLatin1StringView(const QByteArray &s) noexcept
0044         : QLatin1StringView{s.begin(), s.size()} {}
0045     constexpr explicit QLatin1StringView(QByteArrayView s) noexcept
0046         : QLatin1StringView(s.constData(), s.size()) {}
0047 #else
0048     constexpr QLatin1String() noexcept : m_size(0), m_data(nullptr) {}
0049     Q_WEAK_OVERLOAD
0050     constexpr QLatin1String(std::nullptr_t) noexcept : QLatin1String() {}
0051     constexpr explicit QLatin1String(const char *s) noexcept
0052         : m_size(s ? qsizetype(QtPrivate::lengthHelperPointer(s)) : 0), m_data(s) {}
0053     constexpr QLatin1String(const char *f, const char *l)
0054         : QLatin1String(f, qsizetype(l - f)) {}
0055     constexpr QLatin1String(const char *s, qsizetype sz) noexcept : m_size(sz), m_data(s) {}
0056     explicit QLatin1String(const QByteArray &s) noexcept : QLatin1String(s.begin(), s.size()) {}
0057     constexpr explicit QLatin1String(QByteArrayView s) noexcept : m_size(s.size()), m_data(s.data()) {}
0058 #endif // !Q_L1S_VIEW_IS_PRIMARY
0059
0060     inline QString toString() const;
0061     QByteArray toUtf8() const { return QtPrivate::convertToUtf8(*this); }
0062
0063     constexpr const char *latin1() const noexcept { return m_data; }
0064     constexpr qsizetype size() const noexcept { return m_size; }
0065     constexpr const char *data() const noexcept { return m_data; }
0066     [[nodiscard]] constexpr const char *constData() const noexcept { return data(); }
0067     [[nodiscard]] constexpr const char *constBegin() const noexcept { return begin(); }
0068     [[nodiscard]] constexpr const char *constEnd() const noexcept { return end(); }
0069
0070     [[nodiscard]] constexpr QLatin1Char first() const { return front(); }
0071     [[nodiscard]] constexpr QLatin1Char last() const { return back(); }
0072
0073     [[nodiscard]] constexpr qsizetype length() const noexcept { return size(); }
0074
0075     constexpr bool isNull() const noexcept { return !data(); }
0076     constexpr bool isEmpty() const noexcept { return !size(); }
0077
0078     [[nodiscard]] constexpr bool empty() const noexcept { return size() == 0; }
0079
0080     template <typename...Args>
0081     [[nodiscard]] inline QString arg(Args &&...args) const;
0082
0083     [[nodiscard]] constexpr QLatin1Char at(qsizetype i) const
0084     {
0085         Q_ASSERT(i >= 0);
0086         Q_ASSERT(i < size());
0087         return QLatin1Char(m_data[i]);
0088     }
0089     [[nodiscard]] constexpr QLatin1Char operator[](qsizetype i) const { return at(i); }
0090
0091     [[nodiscard]] constexpr QLatin1Char front() const { return at(0); }
0092     [[nodiscard]] constexpr QLatin1Char back() const { return at(size() - 1); }
0093
0094     [[nodiscard]] int compare(QStringView other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0095     { return QtPrivate::compareStrings(*this, other, cs); }
0096     [[nodiscard]] int compare(QLatin1StringView other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0097     { return QtPrivate::compareStrings(*this, other, cs); }
0098     [[nodiscard]] inline int compare(QUtf8StringView other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
0099     [[nodiscard]] constexpr int compare(QChar c) const noexcept
0100     { return isEmpty() ? -1 : front() == c ? int(size() > 1) : uchar(m_data[0]) - c.unicode(); }
0101     [[nodiscard]] int compare(QChar c, Qt::CaseSensitivity cs) const noexcept
0102     { return QtPrivate::compareStrings(*this, QStringView(&c, 1), cs); }
0103
0104     [[nodiscard]] bool startsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0105     { return QtPrivate::startsWith(*this, s, cs); }
0106     [[nodiscard]] bool startsWith(QLatin1StringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0107     { return QtPrivate::startsWith(*this, s, cs); }
0108     [[nodiscard]] constexpr bool startsWith(QChar c) const noexcept
0109     { return !isEmpty() && front() == c; }
0110     [[nodiscard]] bool startsWith(QChar c, Qt::CaseSensitivity cs) const noexcept
0111     { return QtPrivate::startsWith(*this, QStringView(&c, 1), cs); }
0112
0113     [[nodiscard]] bool endsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0114     { return QtPrivate::endsWith(*this, s, cs); }
0115     [[nodiscard]] bool endsWith(QLatin1StringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0116     { return QtPrivate::endsWith(*this, s, cs); }
0117     [[nodiscard]] constexpr bool endsWith(QChar c) const noexcept
0118     { return !isEmpty() && back() == c; }
0119     [[nodiscard]] bool endsWith(QChar c, Qt::CaseSensitivity cs) const noexcept
0120     { return QtPrivate::endsWith(*this, QStringView(&c, 1), cs); }
0121
0122     [[nodiscard]] qsizetype indexOf(QStringView s, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0123     { return QtPrivate::findString(*this, from, s, cs); }
0124     [[nodiscard]] qsizetype indexOf(QLatin1StringView s, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0125     { return QtPrivate::findString(*this, from, s, cs); }
0126     [[nodiscard]] qsizetype indexOf(QChar c, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0127     { return QtPrivate::findString(*this, from, QStringView(&c, 1), cs); }
0128
0129     [[nodiscard]] bool contains(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0130     { return indexOf(s, 0, cs) != -1; }
0131     [[nodiscard]] bool contains(QLatin1StringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0132     { return indexOf(s, 0, cs) != -1; }
0133     [[nodiscard]] bool contains(QChar c, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0134     { return indexOf(QStringView(&c, 1), 0, cs) != -1; }
0135
0136     [[nodiscard]] qsizetype lastIndexOf(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0137     { return lastIndexOf(s, size(), cs); }
0138     [[nodiscard]] qsizetype lastIndexOf(QStringView s, qsizetype from, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0139     { return QtPrivate::lastIndexOf(*this, from, s, cs); }
0140     [[nodiscard]] qsizetype lastIndexOf(QLatin1StringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0141     { return lastIndexOf(s, size(), cs); }
0142     [[nodiscard]] qsizetype lastIndexOf(QLatin1StringView s, qsizetype from, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0143     { return QtPrivate::lastIndexOf(*this, from, s, cs); }
0144     [[nodiscard]] qsizetype lastIndexOf(QChar c, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0145     { return lastIndexOf(c, -1, cs); }
0146     [[nodiscard]] qsizetype lastIndexOf(QChar c, qsizetype from, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0147     { return QtPrivate::lastIndexOf(*this, from, QStringView(&c, 1), cs); }
0148
0149     [[nodiscard]] qsizetype count(QStringView str, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
0150     { return QtPrivate::count(*this, str, cs); }
0151     [[nodiscard]] qsizetype count(QLatin1StringView str, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
0152     { return QtPrivate::count(*this, str, cs); }
0153     [[nodiscard]] qsizetype count(QChar ch, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
0154     { return QtPrivate::count(*this, ch, cs); }
0155
0156     [[nodiscard]] short toShort(bool *ok = nullptr, int base = 10) const
0157     { return QtPrivate::toIntegral<short>(QByteArrayView(*this), ok, base); }
0158     [[nodiscard]] ushort toUShort(bool *ok = nullptr, int base = 10) const
0159     { return QtPrivate::toIntegral<ushort>(QByteArrayView(*this), ok, base); }
0160     [[nodiscard]] int toInt(bool *ok = nullptr, int base = 10) const
0161     { return QtPrivate::toIntegral<int>(QByteArrayView(*this), ok, base); }
0162     [[nodiscard]] uint toUInt(bool *ok = nullptr, int base = 10) const
0163     { return QtPrivate::toIntegral<uint>(QByteArrayView(*this), ok, base); }
0164     [[nodiscard]] long toLong(bool *ok = nullptr, int base = 10) const
0165     { return QtPrivate::toIntegral<long>(QByteArrayView(*this), ok, base); }
0166     [[nodiscard]] ulong toULong(bool *ok = nullptr, int base = 10) const
0167     { return QtPrivate::toIntegral<ulong>(QByteArrayView(*this), ok, base); }
0168     [[nodiscard]] qlonglong toLongLong(bool *ok = nullptr, int base = 10) const
0169     { return QtPrivate::toIntegral<qlonglong>(QByteArrayView(*this), ok, base); }
0170     [[nodiscard]] qulonglong toULongLong(bool *ok = nullptr, int base = 10) const
0171     { return QtPrivate::toIntegral<qulonglong>(QByteArrayView(*this), ok, base); }
0172     [[nodiscard]] float toFloat(bool *ok = nullptr) const
0173     {
0174         const auto r = QtPrivate::toFloat(*this);
0175         if (ok)
0176             *ok = bool(r);
0177         return r.value_or(0.0f);
0178     }
0179     [[nodiscard]] double toDouble(bool *ok = nullptr) const
0180     {
0181         const auto r = QtPrivate::toDouble(*this);
0182         if (ok)
0183             *ok = bool(r);
0184         return r.value_or(0.0);
0185     }
0186
0187     using value_type = const char;
0188     using pointer = value_type*;
0189     using const_pointer = pointer;
0190     using reference = value_type&;
0191     using const_reference = reference;
0192     using iterator = value_type*;
0193     using const_iterator = iterator;
0194     using difference_type = qsizetype; // violates Container concept requirements
0195     using size_type = qsizetype;       // violates Container concept requirements
0196
0197     constexpr const_iterator begin() const noexcept { return data(); }
0198     constexpr const_iterator cbegin() const noexcept { return data(); }
0199     constexpr const_iterator end() const noexcept { return data() + size(); }
0200     constexpr const_iterator cend() const noexcept { return data() + size(); }
0201
0202     using reverse_iterator = std::reverse_iterator<iterator>;
0203     using const_reverse_iterator = reverse_iterator;
0204
0205     const_reverse_iterator rbegin() const noexcept { return const_reverse_iterator(end()); }
0206     const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator(end()); }
0207     const_reverse_iterator rend() const noexcept { return const_reverse_iterator(begin()); }
0208     const_reverse_iterator crend() const noexcept { return const_reverse_iterator(begin()); }
0209
0210     [[nodiscard]] constexpr qsizetype max_size() const noexcept { return maxSize(); }
0211
0212     [[nodiscard]] static constexpr qsizetype maxSize() noexcept
0213     {
0214         // -1 to deal with the pointer one-past-the-end;
0215         return QtPrivate::MaxAllocSize - 1;
0216     }
0217
0218     [[nodiscard]] constexpr QLatin1StringView mid(qsizetype pos, qsizetype n = -1) const
0219     {
0220         using namespace QtPrivate;
0221         auto result = QContainerImplHelper::mid(size(), &pos, &n);
0222         return result == QContainerImplHelper::Null ? QLatin1StringView()
0223                                                     : QLatin1StringView(m_data + pos, n);
0224     }
0225     [[nodiscard]] constexpr QLatin1StringView left(qsizetype n) const
0226     {
0227         if (size_t(n) >= size_t(size()))
0228             n = size();
0229         return {m_data, n};
0230     }
0231     [[nodiscard]] constexpr QLatin1StringView right(qsizetype n) const
0232     {
0233         if (size_t(n) >= size_t(size()))
0234             n = size();
0235         return {m_data + m_size - n, n};
0236     }
0237
0238     [[nodiscard]] constexpr QLatin1StringView sliced(qsizetype pos) const
0239     { verify(pos, 0); return {m_data + pos, m_size - pos}; }
0240     [[nodiscard]] constexpr QLatin1StringView sliced(qsizetype pos, qsizetype n) const
0241     { verify(pos, n); return {m_data + pos, n}; }
0242     [[nodiscard]] constexpr QLatin1StringView first(qsizetype n) const
0243     { verify(0, n); return sliced(0, n); }
0244     [[nodiscard]] constexpr QLatin1StringView last(qsizetype n) const
0245     { verify(0, n); return sliced(size() - n, n); }
0246     [[nodiscard]] constexpr QLatin1StringView chopped(qsizetype n) const
0247     { verify(0, n); return sliced(0, size() - n); }
0248
0249     constexpr QLatin1StringView &slice(qsizetype pos)
0250     { *this = sliced(pos); return *this; }
0251     constexpr QLatin1StringView &slice(qsizetype pos, qsizetype n)
0252     { *this = sliced(pos, n); return *this; }
0253
0254     constexpr void chop(qsizetype n)
0255     { verify(0, n); m_size -= n; }
0256     constexpr void truncate(qsizetype n)
0257     { verify(0, n); m_size = n; }
0258
0259     [[nodiscard]] QLatin1StringView trimmed() const noexcept { return QtPrivate::trimmed(*this); }
0260
0261     template <typename Needle, typename...Flags>
0262     [[nodiscard]] constexpr auto tokenize(Needle &&needle, Flags...flags) const
0263         noexcept(noexcept(qTokenize(std::declval<const QLatin1StringView &>(),
0264                                     std::forward<Needle>(needle), flags...)))
0265             -> decltype(qTokenize(*this, std::forward<Needle>(needle), flags...))
0266     { return qTokenize(*this, std::forward<Needle>(needle), flags...); }
0267
0268     friend bool comparesEqual(const QLatin1StringView &s1, const QLatin1StringView &s2) noexcept
0269     { return s1.size() == s2.size() && QtPrivate::equalStrings(s1, s2); }
0270     friend Qt::strong_ordering
0271     compareThreeWay(const QLatin1StringView &s1, const QLatin1StringView &s2) noexcept
0272     {
0273         const int res = QtPrivate::compareStrings(s1, s2);
0274         return Qt::compareThreeWay(res, 0);
0275     }
0276     Q_DECLARE_STRONGLY_ORDERED(QLatin1StringView)
0277
0278     // QChar <> QLatin1StringView
0279     friend bool comparesEqual(const QLatin1StringView &lhs, QChar rhs) noexcept
0280     { return lhs.size() == 1 && rhs == lhs.front(); }
0281     friend Qt::strong_ordering
0282     compareThreeWay(const QLatin1StringView &lhs, QChar rhs) noexcept
0283     {
0284         // negate, as the helper function expects QChar as lhs
0285         const int res = -compare_helper(&rhs, 1, lhs);
0286         return Qt::compareThreeWay(res, 0);
0287     }
0288     Q_DECLARE_STRONGLY_ORDERED(QLatin1StringView, QChar)
0289
0290     // QStringView <> QLatin1StringView
0291     friend bool comparesEqual(const QLatin1StringView &lhs, const QStringView &rhs) noexcept
0292     { return lhs.size() == rhs.size() && QtPrivate::equalStrings(lhs, rhs); }
0293     friend Qt::strong_ordering
0294     compareThreeWay(const QLatin1StringView &lhs, const QStringView &rhs) noexcept
0295     {
0296         const int res = QtPrivate::compareStrings(lhs, rhs);
0297         return Qt::compareThreeWay(res, 0);
0298     }
0299     Q_DECLARE_STRONGLY_ORDERED(QLatin1StringView, QStringView)
0300
0301     // Reversed helper methods for QStringView <> QLatin1StringView comparison.
0302     // If we do not provide them explicitly, QStringView <> QByteArrayView
0303     // overloads will be selected, which will provide wrong results, because
0304     // they will convert from utf-8
0305     friend bool comparesEqual(const QStringView &lhs, const QLatin1StringView &rhs) noexcept
0306     { return comparesEqual(rhs, lhs); }
0307     friend Qt::strong_ordering
0308     compareThreeWay(const QStringView &lhs, const QLatin1StringView &rhs) noexcept
0309     { return QtOrderingPrivate::reversed(compareThreeWay(rhs, lhs)); }
0310
0311 private:
0312     friend bool comparesEqual(const QLatin1StringView &lhs, const QByteArrayView &rhs) noexcept
0313     { return equal_helper(lhs, rhs.data(), rhs.size()); }
0314     friend Qt::strong_ordering
0315     compareThreeWay(const QLatin1StringView &lhs, const QByteArrayView &rhs) noexcept
0316     {
0317         const int res = compare_helper(lhs, rhs.data(), rhs.size());
0318         return Qt::compareThreeWay(res, 0);
0319     }
0320
0321     // Reversed helper methods for QByteArrayView <> QLatin1StringView comparison.
0322     // If we do not provide them explicitly, QByteArrayView <> QByteArrayView
0323     // overloads will be selected, which will provide wrong results
0324     friend bool comparesEqual(const QByteArrayView &lhs, const QLatin1StringView &rhs) noexcept
0325     { return comparesEqual(rhs, lhs); }
0326     friend Qt::strong_ordering
0327     compareThreeWay(const QByteArrayView &lhs, const QLatin1StringView &rhs) noexcept
0328     { return QtOrderingPrivate::reversed(compareThreeWay(rhs, lhs)); }
0329
0330 public:
0331 #if !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)
0332     Q_DECLARE_STRONGLY_ORDERED(QLatin1StringView, QByteArrayView, QT_ASCII_CAST_WARN)
0333     Q_DECLARE_STRONGLY_ORDERED(QLatin1StringView, QByteArray, QT_ASCII_CAST_WARN)
0334     Q_DECLARE_STRONGLY_ORDERED(QLatin1StringView, const char *, QT_ASCII_CAST_WARN)
0335 #endif // !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)
0336
0337 private:
0338     Q_ALWAYS_INLINE constexpr void verify([[maybe_unused]] qsizetype pos,
0339                                           [[maybe_unused]] qsizetype n = 1) const
0340     {
0341         Q_ASSERT(pos >= 0);
0342         Q_ASSERT(pos <= size());
0343         Q_ASSERT(n >= 0);
0344         Q_ASSERT(n <= size() - pos);
0345     }
0346     static int compare_helper(const QLatin1StringView &s1, const char *s2) noexcept
0347     { return compare_helper(s1, s2, qstrlen(s2)); }
0348     Q_CORE_EXPORT static bool equal_helper(QLatin1StringView s1, const char *s2, qsizetype len) noexcept;
0349     Q_CORE_EXPORT static int compare_helper(const QLatin1StringView &s1, const char *s2, qsizetype len) noexcept;
0350     Q_CORE_EXPORT static int compare_helper(const QChar *data1, qsizetype length1,
0351                                             QLatin1StringView s2,
0352                                             Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
0353 #if QT_VERSION >= QT_VERSION_CHECK(7, 0, 0) || defined(QT_BOOTSTRAPPED)
0354     const char *m_data = nullptr;
0355     qsizetype m_size = 0;
0356 #else
0357     qsizetype m_size;
0358     const char *m_data;
0359 #endif
0360 };
0361 #ifdef Q_L1S_VIEW_IS_PRIMARY
0362 Q_DECLARE_TYPEINFO(QLatin1StringView, Q_RELOCATABLE_TYPE);
0363 #else
0364 Q_DECLARE_TYPEINFO(QLatin1String, Q_RELOCATABLE_TYPE);
0365 #endif
0366
0367 namespace Qt {
0368 inline namespace Literals {
0369 inline namespace StringLiterals {
0370
0371 constexpr inline QLatin1StringView operator""_L1(const char *str, size_t size) noexcept
0372 {
0373     return {str, qsizetype(size)};
0374 }
0375
0376 } // StringLiterals
0377 } // Literals
0378 } // Qt
0379
0380 QT_END_NAMESPACE
0381
0382 #ifdef Q_L1S_VIEW_IS_PRIMARY
0383 #    undef Q_L1S_VIEW_IS_PRIMARY
0384 #endif
0385
0386 #endif // QLATIN1STRINGVIEW_H