1berry/qtbase
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
qtbase/src/corelib/text/qstringview.h
Ahmad Samir f1e15832dd String Views: optimize the QByteArray/QString constructors 
By using {QString,QByteArray}::begin() instead of data() (for const
objectst); both begin() methods, respectively [1], return nullptr for a
const null {QString,QByteArray}. Whereas data() returns &_empty if
QT5_NULL_STRINGS is defined.

[1] QByteArray::begin() since a116b2ddfc9e91736b1ec4edda6500e9c8f5f301
QString::begin() since 287ace562ee5ddff22f7dbf4e49ae5f0520f2308

[ChangeLog][QtCore][QLatin1StringView] Creation of QLatin1StringView
from QByteArray or QByteArrayView now preserves the origin's isNull()
status. This matches the behavior of creating a QUtf8StringView from
those types.

Change-Id: Icbdfe282e315c08ca6a17201bcd32c1a3bba8bf5
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
(cherry picked from commit 221d8fdfb14c16472267320f859105f1a3834952)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
2024-08-26 04:18:29 +00:00

503 lines
23 KiB
C++
Raw Blame History

// Copyright (C) 2020 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Marc Mutz <marc.mutz@kdab.com>
// Copyright (C) 2019 Mail.ru Group.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#ifndef QSTRINGVIEW_H
#define QSTRINGVIEW_H
#include <QtCore/qchar.h>
#include <QtCore/qcompare.h>
#include <QtCore/qbytearray.h>
#include <QtCore/qstringliteral.h>
#include <QtCore/qstringalgorithms.h>
#include <string>
#include <string_view>
#include <QtCore/q20type_traits.h>
#if defined(Q_OS_DARWIN) || defined(Q_QDOC)
Q_FORWARD_DECLARE_CF_TYPE(CFString);
Q_FORWARD_DECLARE_OBJC_CLASS(NSString);
#endif
QT_BEGIN_NAMESPACE
class QString;
class QStringView;
class QRegularExpression;
class QRegularExpressionMatch;
#ifdef Q_QDOC
class QUtf8StringView;
#endif
namespace QtPrivate {
template <typename Char>
struct IsCompatibleCharTypeHelper
: std::integral_constant<bool,
std::is_same<Char, QChar>::value ||
std::is_same<Char, ushort>::value ||
std::is_same<Char, char16_t>::value ||
(std::is_same<Char, wchar_t>::value && sizeof(wchar_t) == sizeof(QChar))> {};
template <typename Char>
struct IsCompatibleCharType
: IsCompatibleCharTypeHelper<q20::remove_cvref_t<Char>> {};
template <typename Pointer>
struct IsCompatiblePointerHelper : std::false_type {};
template <typename Char>
struct IsCompatiblePointerHelper<Char*>
: IsCompatibleCharType<Char> {};
template <typename Pointer>
struct IsCompatiblePointer
: IsCompatiblePointerHelper<q20::remove_cvref_t<Pointer>> {};
template <typename T, typename Enable = void>
struct IsContainerCompatibleWithQStringView : std::false_type {};
template <typename T>
struct IsContainerCompatibleWithQStringView<T, std::enable_if_t<std::conjunction_v<
// lacking concepts and ranges, we accept any T whose std::data yields a suitable pointer ...
IsCompatiblePointer<decltype( std::data(std::declval<const T &>()) )>,
// ... and that has a suitable size ...
std::is_convertible<decltype( std::size(std::declval<const T &>()) ), qsizetype>,
// ... and it's a range as it defines an iterator-like API
IsCompatibleCharType<typename std::iterator_traits<decltype( std::begin(std::declval<const T &>()) )>::value_type>,
std::is_convertible<
decltype( std::begin(std::declval<const T &>()) != std::end(std::declval<const T &>()) ),
bool>,
// These need to be treated specially due to the empty vs null distinction
std::negation<std::is_same<std::decay_t<T>, QString>>,
// Don't make an accidental copy constructor
std::negation<std::is_same<std::decay_t<T>, QStringView>>
>>> : std::true_type {};
} // namespace QtPrivate
class QStringView
{
public:
typedef char16_t storage_type;
typedef const QChar value_type;
typedef std::ptrdiff_t difference_type;
typedef qsizetype size_type;
typedef value_type &reference;
typedef value_type &const_reference;
typedef value_type *pointer;
typedef value_type *const_pointer;
typedef pointer iterator;
typedef const_pointer const_iterator;
typedef std::reverse_iterator<iterator> reverse_iterator;
typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
private:
template <typename Char>
using if_compatible_char = typename std::enable_if<QtPrivate::IsCompatibleCharType<Char>::value, bool>::type;
template <typename Pointer>
using if_compatible_pointer = typename std::enable_if<QtPrivate::IsCompatiblePointer<Pointer>::value, bool>::type;
template <typename T>
using if_compatible_qstring_like = typename std::enable_if<std::is_same<T, QString>::value, bool>::type;
template <typename T>
using if_compatible_container = typename std::enable_if<QtPrivate::IsContainerCompatibleWithQStringView<T>::value, bool>::type;
template <typename Char>
static constexpr qsizetype lengthHelperPointer(const Char *str) noexcept
{
if (q20::is_constant_evaluated())
return QtPrivate::lengthHelperPointer(str);
return QtPrivate::qustrlen(reinterpret_cast<const char16_t *>(str));
}
static qsizetype lengthHelperPointer(const QChar *str) noexcept
{
return QtPrivate::qustrlen(reinterpret_cast<const char16_t *>(str));
}
template <typename Char>
static const storage_type *castHelper(const Char *str) noexcept
{ return reinterpret_cast<const storage_type*>(str); }
static constexpr const storage_type *castHelper(const storage_type *str) noexcept
{ return str; }
public:
constexpr QStringView() noexcept {}
constexpr QStringView(std::nullptr_t) noexcept
: QStringView() {}
template <typename Char, if_compatible_char<Char> = true>
constexpr QStringView(const Char *str, qsizetype len)
#if QT_VERSION >= QT_VERSION_CHECK(7, 0, 0) || defined(QT_BOOTSTRAPPED)
: m_data(castHelper(str)),
m_size((Q_ASSERT(len >= 0), Q_ASSERT(str || !len), len))
#else
: m_size((Q_ASSERT(len >= 0), Q_ASSERT(str || !len), len)),
m_data(castHelper(str))
#endif
{}
template <typename Char, if_compatible_char<Char> = true>
constexpr QStringView(const Char *f, const Char *l)
: QStringView(f, l - f) {}
#ifdef Q_QDOC
template <typename Char, size_t N>
constexpr QStringView(const Char (&array)[N]) noexcept;
template <typename Char>
constexpr QStringView(const Char *str) noexcept;
#else
template <typename Pointer, if_compatible_pointer<Pointer> = true>
constexpr QStringView(const Pointer &str) noexcept
: QStringView(str, str ? lengthHelperPointer(str) : 0) {}
#endif
#ifdef Q_QDOC
QStringView(const QString &str) noexcept;
#else
template <typename String, if_compatible_qstring_like<String> = true>
QStringView(const String &str) noexcept
: QStringView{str.begin(), str.size()} {}
#endif
template <typename Container, if_compatible_container<Container> = true>
constexpr Q_ALWAYS_INLINE QStringView(const Container &c) noexcept
: QStringView(std::data(c), QtPrivate::lengthHelperContainer(c)) {}
template <typename Char, size_t Size, if_compatible_char<Char> = true>
[[nodiscard]] constexpr static QStringView fromArray(const Char (&string)[Size]) noexcept
{ return QStringView(string, Size); }
[[nodiscard]] inline QString toString() const; // defined in qstring.h
#if defined(Q_OS_DARWIN) || defined(Q_QDOC)
// defined in qcore_foundation.mm
[[nodiscard]] Q_CORE_EXPORT CFStringRef toCFString() const Q_DECL_CF_RETURNS_RETAINED;
[[nodiscard]] Q_CORE_EXPORT NSString *toNSString() const Q_DECL_NS_RETURNS_AUTORELEASED;
#endif
[[nodiscard]] constexpr qsizetype size() const noexcept { return m_size; }
[[nodiscard]] const_pointer data() const noexcept { return reinterpret_cast<const_pointer>(m_data); }
[[nodiscard]] const_pointer constData() const noexcept { return data(); }
[[nodiscard]] constexpr const storage_type *utf16() const noexcept { return m_data; }
[[nodiscard]] constexpr QChar operator[](qsizetype n) const
{ verify(n, 1); return QChar(m_data[n]); }
//
// QString API
//
template <typename...Args>
[[nodiscard]] inline QString arg(Args &&...args) const; // defined in qstring.h
[[nodiscard]] QByteArray toLatin1() const { return QtPrivate::convertToLatin1(*this); }
[[nodiscard]] QByteArray toUtf8() const { return QtPrivate::convertToUtf8(*this); }
[[nodiscard]] QByteArray toLocal8Bit() const { return QtPrivate::convertToLocal8Bit(*this); }
[[nodiscard]] inline QList<uint> toUcs4() const; // defined in qlist.h ### Qt 7 char32_t
[[nodiscard]] constexpr QChar at(qsizetype n) const noexcept { return (*this)[n]; }
[[nodiscard]] constexpr QStringView mid(qsizetype pos, qsizetype n = -1) const noexcept
{
using namespace QtPrivate;
auto result = QContainerImplHelper::mid(size(), &pos, &n);
return result == QContainerImplHelper::Null ? QStringView() : QStringView(m_data + pos, n);
}
[[nodiscard]] constexpr QStringView left(qsizetype n) const noexcept
{
if (size_t(n) >= size_t(size()))
n = size();
return QStringView(m_data, n);
}
[[nodiscard]] constexpr QStringView right(qsizetype n) const noexcept
{
if (size_t(n) >= size_t(size()))
n = size();
return QStringView(m_data + m_size - n, n);
}
[[nodiscard]] constexpr QStringView first(qsizetype n) const noexcept
{ verify(0, n); return sliced(0, n); }
[[nodiscard]] constexpr QStringView last(qsizetype n) const noexcept
{ verify(0, n); return sliced(size() - n, n); }
[[nodiscard]] constexpr QStringView sliced(qsizetype pos) const noexcept
{ verify(pos, 0); return QStringView(m_data + pos, size() - pos); }
[[nodiscard]] constexpr QStringView sliced(qsizetype pos, qsizetype n) const noexcept
{ verify(pos, n); return QStringView(m_data + pos, n); }
[[nodiscard]] constexpr QStringView chopped(qsizetype n) const noexcept
{ verify(0, n); return sliced(0, m_size - n); }
constexpr void truncate(qsizetype n) noexcept
{ verify(0, n); ; m_size = n; }
constexpr void chop(qsizetype n) noexcept
{ verify(0, n); m_size -= n; }
[[nodiscard]] QStringView trimmed() const noexcept { return QtPrivate::trimmed(*this); }
template <typename Needle, typename...Flags>
[[nodiscard]] constexpr inline auto tokenize(Needle &&needle, Flags...flags) const
noexcept(noexcept(qTokenize(std::declval<const QStringView&>(), std::forward<Needle>(needle), flags...)))
-> decltype(qTokenize(*this, std::forward<Needle>(needle), flags...))
{ return qTokenize(*this, std::forward<Needle>(needle), flags...); }
[[nodiscard]] int compare(QStringView other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
{ return QtPrivate::compareStrings(*this, other, cs); }
[[nodiscard]] inline int compare(QLatin1StringView other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
[[nodiscard]] inline int compare(QUtf8StringView other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
[[nodiscard]] constexpr int compare(QChar c) const noexcept
{ return size() >= 1 ? compare_single_char_helper(*utf16() - c.unicode()) : -1; }
[[nodiscard]] int compare(QChar c, Qt::CaseSensitivity cs) const noexcept
{ return QtPrivate::compareStrings(*this, QStringView(&c, 1), cs); }
[[nodiscard]] inline int localeAwareCompare(QStringView other) const;
[[nodiscard]] bool startsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
{ return QtPrivate::startsWith(*this, s, cs); }
[[nodiscard]] inline bool startsWith(QLatin1StringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
[[nodiscard]] bool startsWith(QChar c) const noexcept
{ return !empty() && front() == c; }
[[nodiscard]] bool startsWith(QChar c, Qt::CaseSensitivity cs) const noexcept
{ return QtPrivate::startsWith(*this, QStringView(&c, 1), cs); }
[[nodiscard]] bool endsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
{ return QtPrivate::endsWith(*this, s, cs); }
[[nodiscard]] inline bool endsWith(QLatin1StringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
[[nodiscard]] bool endsWith(QChar c) const noexcept
{ return !empty() && back() == c; }
[[nodiscard]] bool endsWith(QChar c, Qt::CaseSensitivity cs) const noexcept
{ return QtPrivate::endsWith(*this, QStringView(&c, 1), cs); }
[[nodiscard]] qsizetype indexOf(QChar c, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
{ return QtPrivate::findString(*this, from, c.unicode(), cs); }
[[nodiscard]] qsizetype indexOf(QStringView s, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
{ return QtPrivate::findString(*this, from, s, cs); }
[[nodiscard]] inline qsizetype indexOf(QLatin1StringView s, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
[[nodiscard]] bool contains(QChar c, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
{ return indexOf(QStringView(&c, 1), 0, cs) != qsizetype(-1); }
[[nodiscard]] bool contains(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
{ return indexOf(s, 0, cs) != qsizetype(-1); }
[[nodiscard]] inline bool contains(QLatin1StringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
[[nodiscard]] qsizetype count(QChar c, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
{ return QtPrivate::count(*this, c, cs); }
[[nodiscard]] qsizetype count(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
{ return QtPrivate::count(*this, s, cs); }
[[nodiscard]] inline qsizetype count(QLatin1StringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
[[nodiscard]] qsizetype lastIndexOf(QChar c, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
{ return lastIndexOf(c, -1, cs); }
[[nodiscard]] qsizetype lastIndexOf(QChar c, qsizetype from, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
{ return QtPrivate::lastIndexOf(*this, from, c.unicode(), cs); }
[[nodiscard]] qsizetype lastIndexOf(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
{ return lastIndexOf(s, size(), cs); }
[[nodiscard]] qsizetype lastIndexOf(QStringView s, qsizetype from, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
{ return QtPrivate::lastIndexOf(*this, from, s, cs); }
[[nodiscard]] inline qsizetype lastIndexOf(QLatin1StringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
[[nodiscard]] inline qsizetype lastIndexOf(QLatin1StringView s, qsizetype from, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
#if QT_CONFIG(regularexpression)
[[nodiscard]] qsizetype indexOf(const QRegularExpression &re, qsizetype from = 0, QRegularExpressionMatch *rmatch = nullptr) const
{
return QtPrivate::indexOf(*this, re, from, rmatch);
}
#ifdef Q_QDOC
[[nodiscard]] qsizetype lastIndexOf(const QRegularExpression &re, QRegularExpressionMatch *rmatch = nullptr) const;
#else
// prevent an ambiguity when called like this: lastIndexOf(re, 0)
template <typename T = QRegularExpressionMatch, std::enable_if_t<std::is_same_v<T, QRegularExpressionMatch>, bool> = false>
[[nodiscard]] qsizetype lastIndexOf(const QRegularExpression &re, T *rmatch = nullptr) const
{
return QtPrivate::lastIndexOf(*this, re, size(), rmatch);
}
#endif
[[nodiscard]] qsizetype lastIndexOf(const QRegularExpression &re, qsizetype from, QRegularExpressionMatch *rmatch = nullptr) const
{
return QtPrivate::lastIndexOf(*this, re, from, rmatch);
}
[[nodiscard]] bool contains(const QRegularExpression &re, QRegularExpressionMatch *rmatch = nullptr) const
{
return QtPrivate::contains(*this, re, rmatch);
}
[[nodiscard]] qsizetype count(const QRegularExpression &re) const
{
return QtPrivate::count(*this, re);
}
#endif
[[nodiscard]] bool isRightToLeft() const noexcept
{ return QtPrivate::isRightToLeft(*this); }
[[nodiscard]] bool isValidUtf16() const noexcept
{ return QtPrivate::isValidUtf16(*this); }
[[nodiscard]] bool isUpper() const noexcept
{ return QtPrivate::isUpper(*this); }
[[nodiscard]] bool isLower() const noexcept
{ return QtPrivate::isLower(*this); }
[[nodiscard]] inline short toShort(bool *ok = nullptr, int base = 10) const;
[[nodiscard]] inline ushort toUShort(bool *ok = nullptr, int base = 10) const;
[[nodiscard]] inline int toInt(bool *ok = nullptr, int base = 10) const;
[[nodiscard]] inline uint toUInt(bool *ok = nullptr, int base = 10) const;
[[nodiscard]] inline long toLong(bool *ok = nullptr, int base = 10) const;
[[nodiscard]] inline ulong toULong(bool *ok = nullptr, int base = 10) const;
[[nodiscard]] inline qlonglong toLongLong(bool *ok = nullptr, int base = 10) const;
[[nodiscard]] inline qulonglong toULongLong(bool *ok = nullptr, int base = 10) const;
[[nodiscard]] Q_CORE_EXPORT float toFloat(bool *ok = nullptr) const;
[[nodiscard]] Q_CORE_EXPORT double toDouble(bool *ok = nullptr) const;
[[nodiscard]] inline qsizetype toWCharArray(wchar_t *array) const; // defined in qstring.h
[[nodiscard]] Q_CORE_EXPORT
QList<QStringView> split(QStringView sep,
Qt::SplitBehavior behavior = Qt::KeepEmptyParts,
Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
[[nodiscard]] Q_CORE_EXPORT
QList<QStringView> split(QChar sep, Qt::SplitBehavior behavior = Qt::KeepEmptyParts,
Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
#if QT_CONFIG(regularexpression)
[[nodiscard]] Q_CORE_EXPORT
QList<QStringView> split(const QRegularExpression &sep,
Qt::SplitBehavior behavior = Qt::KeepEmptyParts) const;
#endif
// QStringView <> QStringView
friend bool comparesEqual(const QStringView &lhs, const QStringView &rhs) noexcept
{ return lhs.size() == rhs.size() && QtPrivate::equalStrings(lhs, rhs); }
friend Qt::strong_ordering
compareThreeWay(const QStringView &lhs, const QStringView &rhs) noexcept
{
const int res = QtPrivate::compareStrings(lhs, rhs);
return Qt::compareThreeWay(res, 0);
}
Q_DECLARE_STRONGLY_ORDERED(QStringView)
// QStringView <> QChar
friend bool comparesEqual(const QStringView &lhs, QChar rhs) noexcept
{ return lhs.size() == 1 && lhs[0] == rhs; }
friend Qt::strong_ordering compareThreeWay(const QStringView &lhs, QChar rhs) noexcept
{ return compareThreeWay(lhs, QStringView(&rhs, 1)); }
Q_DECLARE_STRONGLY_ORDERED(QStringView, QChar)
//
// STL compatibility API:
//
[[nodiscard]] const_iterator begin() const noexcept { return data(); }
[[nodiscard]] const_iterator end() const noexcept { return data() + size(); }
[[nodiscard]] const_iterator cbegin() const noexcept { return begin(); }
[[nodiscard]] const_iterator cend() const noexcept { return end(); }
[[nodiscard]] const_reverse_iterator rbegin() const noexcept { return const_reverse_iterator(end()); }
[[nodiscard]] const_reverse_iterator rend() const noexcept { return const_reverse_iterator(begin()); }
[[nodiscard]] const_reverse_iterator crbegin() const noexcept { return rbegin(); }
[[nodiscard]] const_reverse_iterator crend() const noexcept { return rend(); }
[[nodiscard]] constexpr bool empty() const noexcept { return size() == 0; }
[[nodiscard]] constexpr QChar front() const { return Q_ASSERT(!empty()), QChar(m_data[0]); }
[[nodiscard]] constexpr QChar back() const { return Q_ASSERT(!empty()), QChar(m_data[m_size - 1]); }
[[nodiscard]] Q_IMPLICIT operator std::u16string_view() const noexcept
{ return std::u16string_view(m_data, size_t(m_size)); }
//
// Qt compatibility API:
//
[[nodiscard]] const_iterator constBegin() const noexcept { return begin(); }
[[nodiscard]] const_iterator constEnd() const noexcept { return end(); }
[[nodiscard]] constexpr bool isNull() const noexcept { return !m_data; }
[[nodiscard]] constexpr bool isEmpty() const noexcept { return empty(); }
[[nodiscard]] constexpr qsizetype length() const noexcept
{ return size(); }
[[nodiscard]] constexpr QChar first() const { return front(); }
[[nodiscard]] constexpr QChar last() const { return back(); }
private:
#if QT_VERSION >= QT_VERSION_CHECK(7, 0, 0) || defined(QT_BOOTSTRAPPED)
const storage_type *m_data = nullptr;
qsizetype m_size = 0;
#else
qsizetype m_size = 0;
const storage_type *m_data = nullptr;
#endif
Q_ALWAYS_INLINE constexpr void verify([[maybe_unused]] qsizetype pos = 0,
[[maybe_unused]] qsizetype n = 1) const
{
Q_ASSERT(pos >= 0);
Q_ASSERT(pos <= size());
Q_ASSERT(n >= 0);
Q_ASSERT(n <= size() - pos);
}
constexpr int compare_single_char_helper(int diff) const noexcept
{ return diff ? diff : size() > 1 ? 1 : 0; }
Q_CORE_EXPORT static bool equal_helper(QStringView sv, const char *data, qsizetype len);
Q_CORE_EXPORT static int compare_helper(QStringView sv, const char *data, qsizetype len);
#if !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)
friend bool comparesEqual(const QStringView &lhs, const QByteArrayView &rhs) noexcept
{ return equal_helper(lhs, rhs.data(), rhs.size()); }
friend Qt::strong_ordering
compareThreeWay(const QStringView &lhs, const QByteArrayView &rhs) noexcept
{
const int res = compare_helper(lhs, rhs.data(), rhs.size());
return Qt::compareThreeWay(res, 0);
}
Q_DECLARE_STRONGLY_ORDERED(QStringView, QByteArrayView, QT_ASCII_CAST_WARN)
Q_DECLARE_STRONGLY_ORDERED(QStringView, QByteArray, QT_ASCII_CAST_WARN)
Q_DECLARE_STRONGLY_ORDERED(QStringView, const char *, QT_ASCII_CAST_WARN)
#endif // !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)
};
Q_DECLARE_TYPEINFO(QStringView, Q_PRIMITIVE_TYPE);
template <typename QStringLike, typename std::enable_if<
std::is_same<QStringLike, QString>::value,
bool>::type = true>
inline QStringView qToStringViewIgnoringNull(const QStringLike &s) noexcept
{ return QStringView(s.begin(), s.size()); }
// QChar inline functions:
[[nodiscard]] constexpr auto QChar::fromUcs4(char32_t c) noexcept
{
struct R {
char16_t chars[2];
[[nodiscard]] constexpr operator QStringView() const noexcept { return {begin(), end()}; }
[[nodiscard]] constexpr qsizetype size() const noexcept { return chars[1] ? 2 : 1; }
[[nodiscard]] constexpr const char16_t *begin() const noexcept { return chars; }
[[nodiscard]] constexpr const char16_t *end() const noexcept { return begin() + size(); }
};
return requiresSurrogates(c) ? R{{QChar::highSurrogate(c),
QChar::lowSurrogate(c)}} :
R{{char16_t(c), u'\0'}} ;
}
qsizetype QtPrivate::findString(QStringView str, qsizetype from, QChar ch, Qt::CaseSensitivity cs) noexcept
{
if (from < -str.size()) // from < 0 && abs(from) > str.size(), avoiding overflow
return -1;
if (from < 0)
from = qMax(from + str.size(), qsizetype(0));
if (from < str.size()) {
const char16_t *s = str.utf16();
char16_t c = ch.unicode();
const char16_t *n = s + from;
const char16_t *e = s + str.size();
if (cs == Qt::CaseSensitive)
n = qustrchr(QStringView(n, e), c);
else
n = qustrcasechr(QStringView(n, e), c);
if (n != e)
return n - s;
}
return -1;
}
QT_END_NAMESPACE
#endif /* QSTRINGVIEW_H */
Reference in New Issue View Git Blame Copy Permalink