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qt6-bb10/src/corelib/text/qstringview.cpp

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/****************************************************************************
**
** Copyright (C) 2017 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Marc Mutz <marc.mutz@kdab.com>
** Contact: http://www.qt.io/licensing/
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
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** accordance with the commercial license agreement provided with the
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** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
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** $QT_END_LICENSE$
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****************************************************************************/
#include "qstringview.h"
#include "qstring.h"
#include "qlocale_p.h"
QT_BEGIN_NAMESPACE
/*!
\class QStringView
\inmodule QtCore
\since 5.10
\brief The QStringView class provides a unified view on UTF-16 strings with a read-only subset of the QString API.
\reentrant
\ingroup tools
\ingroup string-processing
A QStringView references a contiguous portion of a UTF-16 string it does
not own. It acts as an interface type to all kinds of UTF-16 string,
without the need to construct a QString first.
The UTF-16 string may be represented as an array (or an array-compatible
data-structure such as QString,
std::basic_string, etc.) of QChar, \c ushort, \c char16_t or
(on platforms, such as Windows, where it is a 16-bit type) \c wchar_t.
QStringView is designed as an interface type; its main use-case is
as a function parameter type. When QStringViews are used as automatic
variables or data members, care must be taken to ensure that the referenced
string data (for example, owned by a QString) outlives the QStringView on all code paths,
lest the string view ends up referencing deleted data.
When used as an interface type, QStringView allows a single function to accept
a wide variety of UTF-16 string data sources. One function accepting QStringView
thus replaces three function overloads (taking QString and
\c{(const QChar*, int)}), while at the same time enabling even more string data
sources to be passed to the function, such as \c{u"Hello World"}, a \c char16_t
string literal.
QStringViews should be passed by value, not by reference-to-const:
\snippet code/src_corelib_text_qstringview.cpp 0
If you want to give your users maximum freedom in what strings they can pass
to your function, accompany the QStringView overload with overloads for
\list
\li \e QChar: this overload can delegate to the QStringView version:
\snippet code/src_corelib_text_qstringview.cpp 1
even though, for technical reasons, QStringView cannot provide a
QChar constructor by itself.
\li \e QString: if you store an unmodified copy of the string and thus would
like to take advantage of QString's implicit sharing.
\li QLatin1String: if you can implement the function without converting the
QLatin1String to UTF-16 first; users expect a function overloaded on
QLatin1String to perform strictly less memory allocations than the
semantically equivalent call of the QStringView version, involving
construction of a QString from the QLatin1String.
\endlist
QStringView can also be used as the return value of a function. If you call a
function returning QStringView, take extra care to not keep the QStringView
around longer than the function promises to keep the referenced string data alive.
If in doubt, obtain a strong reference to the data by calling toString() to convert
the QStringView into a QString.
QStringView is a \e{Literal Type}, but since it stores data as \c{char16_t}, iteration
is not \c constexpr (casts from \c{const char16_t*} to \c{const QChar*}, which is not
allowed in \c constexpr functions). You can use an indexed loop and/or utf16() in
\c constexpr contexts instead.
\sa QString
*/
/*!
\typedef QStringView::storage_type
Alias for \c{char16_t}.
*/
/*!
\typedef QStringView::value_type
Alias for \c{const QChar}. Provided for compatibility with the STL.
*/
/*!
\typedef QStringView::difference_type
Alias for \c{std::ptrdiff_t}. Provided for compatibility with the STL.
*/
/*!
\typedef QStringView::size_type
Alias for qsizetype. Provided for compatibility with the STL.
Unlike other Qt classes, QStringView uses qsizetype as its \c size_type, to allow
accepting data from \c{std::basic_string} without truncation. The Qt API functions,
for example length(), return \c int, while the STL-compatible functions, for example
size(), return \c size_type.
*/
/*!
\typedef QStringView::reference
Alias for \c{value_type &}. Provided for compatibility with the STL.
QStringView does not support mutable references, so this is the same
as const_reference.
*/
/*!
\typedef QStringView::const_reference
Alias for \c{value_type &}. Provided for compatibility with the STL.
*/
/*!
\typedef QStringView::pointer
Alias for \c{value_type *}. Provided for compatibility with the STL.
QStringView does not support mutable pointers, so this is the same
as const_pointer.
*/
/*!
\typedef QStringView::const_pointer
Alias for \c{value_type *}. Provided for compatibility with the STL.
*/
/*!
\typedef QStringView::iterator
This typedef provides an STL-style const iterator for QStringView.
QStringView does not support mutable iterators, so this is the same
as const_iterator.
\sa const_iterator, reverse_iterator
*/
/*!
\typedef QStringView::const_iterator
This typedef provides an STL-style const iterator for QStringView.
\sa iterator, const_reverse_iterator
*/
/*!
\typedef QStringView::reverse_iterator
This typedef provides an STL-style const reverse iterator for QStringView.
QStringView does not support mutable reverse iterators, so this is the
same as const_reverse_iterator.
\sa const_reverse_iterator, iterator
*/
/*!
\typedef QStringView::const_reverse_iterator
This typedef provides an STL-style const reverse iterator for QStringView.
\sa reverse_iterator, const_iterator
*/
/*!
\fn QStringView::QStringView()
Constructs a null string view.
\sa isNull()
*/
/*!
\fn QStringView::QStringView(std::nullptr_t)
Constructs a null string view.
\sa isNull()
*/
/*!
\fn template <typename Char> QStringView::QStringView(const Char *str, qsizetype len)
Constructs a string view on \a str with length \a len.
The range \c{[str,len)} must remain valid for the lifetime of this string view object.
Passing \nullptr as \a str is safe if \a len is 0, too, and results in a null string view.
The behavior is undefined if \a len is negative or, when positive, if \a str is \nullptr.
This constructor only participates in overload resolution if \c Char is a compatible
character type. The compatible character types are: \c QChar, \c ushort, \c char16_t and
(on platforms, such as Windows, where it is a 16-bit type) \c wchar_t.
*/
/*!
\fn template <typename Char> QStringView::QStringView(const Char *first, const Char *last)
Constructs a string view on \a first with length (\a last - \a first).
The range \c{[first,last)} must remain valid for the lifetime of
this string view object.
Passing \c \nullptr as \a first is safe if \a last is \nullptr, too,
and results in a null string view.
The behavior is undefined if \a last precedes \a first, or \a first
is \nullptr and \a last is not.
This constructor only participates in overload resolution if \c Char
is a compatible character type. The compatible character types
are: \c QChar, \c ushort, \c char16_t and (on platforms, such as
Windows, where it is a 16-bit type) \c wchar_t.
*/
/*!
\fn template <typename Char> QStringView::QStringView(const Char *str)
Constructs a string view on \a str. The length is determined
by scanning for the first \c{Char(0)}.
\a str must remain valid for the lifetime of this string view object.
Passing \nullptr as \a str is safe and results in a null string view.
This constructor only participates in overload resolution if \a
str is not an array and if \c Char is a compatible character
type. The compatible character types are: \c QChar, \c ushort, \c
char16_t and (on platforms, such as Windows, where it is a 16-bit
type) \c wchar_t.
*/
/*!
\fn template <typename Char, size_t N> QStringView::QStringView(const Char (&string)[N])
Constructs a string view on the character string literal \a string.
The view covers the array until the first \c{Char(0)} is encountered,
or \c N, whichever comes first.
If you need the full array, use fromArray() instead.
\a string must remain valid for the lifetime of this string view
object.
This constructor only participates in overload resolution if \a
string is an actual array and \c Char is a compatible character
type. The compatible character types are: \c QChar, \c ushort, \c
char16_t and (on platforms, such as Windows, where it is a 16-bit
type) \c wchar_t.
\sa fromArray
*/
/*!
\fn QStringView::QStringView(const QString &str)
Constructs a string view on \a str.
\c{str.data()} must remain valid for the lifetime of this string view object.
The string view will be null if and only if \c{str.isNull()}.
*/
/*!
\fn template <typename Container, if_compatible_container<Container>> QStringView::QStringView(const Container &str)
Constructs a string view on \a str. The length is taken from \c{str.size()}.
\c{str.data()} must remain valid for the lifetime of this string view object.
This constructor only participates in overload resolution if \c StdBasicString is an
instantiation of \c std::basic_string with a compatible character type. The
compatible character types are: \c QChar, \c ushort, \c char16_t and
(on platforms, such as Windows, where it is a 16-bit type) \c wchar_t.
The string view will be empty if and only if \c{str.empty()}. It is unspecified
whether this constructor can result in a null string view (\c{str.data()} would
have to return \nullptr for this).
\sa isNull(), isEmpty()
*/
/*!
\fn template <typename Char, size_t Size> static QStringView QStringView::fromArray(const Char (&string)[Size]) noexcept
Constructs a string view on the full character string literal \a string,
including any trailing \c{Char(0)}. If you don't want the
null-terminator included in the view then you can chop() it off
when you are certain it is at the end. Alternatively you can use
the constructor overload taking an array literal which will create
a view up to, but not including, the first null-terminator in the data.
\a string must remain valid for the lifetime of this string view
object.
This function will work with any array literal if \c Char is a
compatible character type. The compatible character types are: \c QChar, \c ushort, \c
char16_t and (on platforms, such as Windows, where it is a 16-bit
type) \c wchar_t.
*/
/*!
\fn QString QStringView::toString() const
Returns a deep copy of this string view's data as a QString.
The return value will be the null QString if and only if this string view is null.
\warning QStringView can store strings with more than 2\sup{30} characters
while QString cannot. Calling this function on a string view for which size()
returns a value greater than \c{INT_MAX / 2} constitutes undefined behavior.
*/
/*!
\fn const QChar *QStringView::data() const
Returns a const pointer to the first character in the string.
\note The character array represented by the return value is \e not null-terminated.
\sa begin(), end(), utf16()
*/
/*!
\fn const QChar *QStringView::constData() const
\since 6.0
Returns a const pointer to the first character in the string.
\note The character array represented by the return value is \e not null-terminated.
\sa data(), begin(), end(), utf16()
*/
/*!
\fn const storage_type *QStringView::utf16() const
Returns a const pointer to the first character in the string.
\c{storage_type} is \c{char16_t}.
\note The character array represented by the return value is \e not null-terminated.
\sa begin(), end(), data()
*/
/*!
\fn QStringView::const_iterator QStringView::begin() const
Returns a const \l{STL-style iterators}{STL-style iterator} pointing to the first character in
the string.
This function is provided for STL compatibility.
\sa end(), cbegin(), rbegin(), data()
*/
/*!
\fn QStringView::const_iterator QStringView::cbegin() const
Same as begin().
This function is provided for STL compatibility.
\sa cend(), begin(), crbegin(), data()
*/
/*!
\fn QStringView::const_iterator QStringView::end() const
Returns a const \l{STL-style iterators}{STL-style iterator} pointing to the imaginary
character after the last character in the list.
This function is provided for STL compatibility.
\sa begin(), cend(), rend()
*/
/*! \fn QStringView::const_iterator QStringView::cend() const
Same as end().
This function is provided for STL compatibility.
\sa cbegin(), end(), crend()
*/
/*!
\fn QStringView::const_reverse_iterator QStringView::rbegin() const
Returns a const \l{STL-style iterators}{STL-style} reverse iterator pointing to the first
character in the string, in reverse order.
This function is provided for STL compatibility.
\sa rend(), crbegin(), begin()
*/
/*!
\fn QStringView::const_reverse_iterator QStringView::crbegin() const
Same as rbegin().
This function is provided for STL compatibility.
\sa crend(), rbegin(), cbegin()
*/
/*!
\fn QStringView::const_reverse_iterator QStringView::rend() const
Returns a \l{STL-style iterators}{STL-style} reverse iterator pointing to one past
the last character in the string, in reverse order.
This function is provided for STL compatibility.
\sa rbegin(), crend(), end()
*/
/*!
\fn QStringView::const_reverse_iterator QStringView::crend() const
Same as rend().
This function is provided for STL compatibility.
\sa crbegin(), rend(), cend()
*/
/*!
\fn bool QStringView::empty() const
Returns whether this string view is empty - that is, whether \c{size() == 0}.
This function is provided for STL compatibility.
\sa isEmpty(), isNull(), size(), length()
*/
/*!
\fn bool QStringView::isEmpty() const
Returns whether this string view is empty - that is, whether \c{size() == 0}.
This function is provided for compatibility with other Qt containers.
\sa empty(), isNull(), size(), length()
*/
/*!
\fn bool QStringView::isNull() const
Returns whether this string view is null - that is, whether \c{data() == nullptr}.
This functions is provided for compatibility with other Qt containers.
\sa empty(), isEmpty(), size(), length()
*/
/*!
\fn qsizetype QStringView::size() const
Returns the size of this string view, in UTF-16 code points (that is,
surrogate pairs count as two for the purposes of this function, the same
as in QString).
\sa empty(), isEmpty(), isNull(), length()
*/
/*!
\fn int QStringView::length() const
Same as size(), except returns the result as an \c int.
This function is provided for compatibility with other Qt containers.
\warning QStringView can represent strings with more than 2\sup{31} characters.
Calling this function on a string view for which size() returns a value greater
than \c{INT_MAX} constitutes undefined behavior.
\sa empty(), isEmpty(), isNull(), size()
*/
/*!
\fn QChar QStringView::operator[](qsizetype n) const
Returns the character at position \a n in this string view.
The behavior is undefined if \a n is negative or not less than size().
\sa at(), front(), back()
*/
/*!
\fn QChar QStringView::at(qsizetype n) const
Returns the character at position \a n in this string view.
The behavior is undefined if \a n is negative or not less than size().
\sa operator[](), front(), back()
*/
/*!
\fn template <typename...Args> QString QStringView::arg(Args &&...args) const
\fn template <typename...Args> QString QLatin1String::arg(Args &&...args) const
\fn template <typename...Args> QString QString::arg(Args &&...args) const
\since 5.14
Replaces occurrences of \c{%N} in this string with the corresponding
argument from \a args. The arguments are not positional: the first of
the \a args replaces the \c{%N} with the lowest \c{N} (all of them), the
second of the \a args the \c{%N} with the next-lowest \c{N} etc.
\c Args can consist of anything that implicitly converts to QString,
QStringView or QLatin1String.
In addition, the following types are also supported: QChar, QLatin1Char.
\sa QString::arg()
*/
/*!
\fn QChar QStringView::front() const
Returns the first character in the string. Same as first().
This function is provided for STL compatibility.
\warning Calling this function on an empty string view constitutes
undefined behavior.
\sa back(), first(), last()
*/
/*!
\fn QChar QStringView::back() const
Returns the last character in the string. Same as last().
This function is provided for STL compatibility.
\warning Calling this function on an empty string view constitutes
undefined behavior.
\sa front(), first(), last()
*/
/*!
\fn QChar QStringView::first() const
Returns the first character in the string. Same as front().
This function is provided for compatibility with other Qt containers.
\warning Calling this function on an empty string view constitutes
undefined behavior.
\sa front(), back(), last()
*/
/*!
\fn QChar QStringView::last() const
Returns the last character in the string. Same as back().
This function is provided for compatibility with other Qt containers.
\warning Calling this function on an empty string view constitutes
undefined behavior.
\sa back(), front(), first()
*/
/*!
\fn QStringView QStringView::mid(qsizetype start, qsizetype length) const
Returns the substring of length \a length starting at position
\a start in this object.
\obsolete Use sliced() instead in new code.
Returns an empty string view if \a start exceeds the
length of the string. If there are less than \a length characters
available in the string starting at \a start, or if
\a length is negative (default), the function returns all characters that
are available from \a start.
\sa first(), last(), sliced(), chopped(), chop(), truncate()
*/
/*!
\fn QStringView QStringView::left(qsizetype length) const
\obsolete Use first() instead in new code.
Returns the substring of length \a length starting at position
0 in this object.
The entire string is returned if \a length is greater than or equal
to size(), or less than zero.
\sa first(), last(), sliced(), startsWith(), chopped(), chop(), truncate()
*/
/*!
\fn QStringView QStringView::right(qsizetype length) const
\obsolete Use last() instead in new code.
Returns the substring of length \a length starting at position
size() - \a length in this object.
The entire string is returned if \a length is greater than or equal
to size(), or less than zero.
\sa first(), last(), sliced(), endsWith(), chopped(), chop(), truncate()
*/
/*!
\fn QStringView QStringView::first(qsizetype n) const
\since 6.0
Returns a string view that points to the first \a n characters
of this string.
\note The behavior is undefined when \a n < 0 or \a n > size().
\sa last(), sliced(), startsWith(), chopped(), chop(), truncate()
*/
/*!
\fn QStringView QStringView::last(qsizetype n) const
\since 6.0
Returns a string view that points to the last \a n characters of this string.
\note The behavior is undefined when \a n < 0 or \a n > size().
\sa first(), sliced(), endsWith(), chopped(), chop(), truncate()
*/
/*!
\fn QStringView QStringView::sliced(qsizetype pos, qsizetype n) const
\since 6.0
Returns a string view that points to \a n characters of this string,
starting at position \a pos.
\note The behavior is undefined when \a pos < 0, \a n < 0,
or \a pos + \a n > size().
\sa first(), last(), chopped(), chop(), truncate()
*/
/*!
\fn QStringView QStringView::sliced(qsizetype pos) const
\since 6.0
\overload
Returns a string view starting at position \a pos in this object,
and extending to its end.
\note The behavior is undefined when \a pos < 0 or \a pos > size().
\sa first(), last(), chopped(), chop(), truncate()
*/
/*!
\fn QStringView QStringView::chopped(qsizetype length) const
Returns the substring of length size() - \a length starting at the
beginning of this object.
Same as \c{left(size() - length)}.
\note The behavior is undefined when \a length < 0 or \a length > size().
\sa mid(), left(), right(), chop(), truncate()
*/
/*!
\fn void QStringView::truncate(qsizetype length)
Truncates this string view to length \a length.
Same as \c{*this = left(length)}.
\note The behavior is undefined when \a length < 0 or \a length > size().
\sa mid(), left(), right(), chopped(), chop()
*/
/*!
\fn void QStringView::chop(qsizetype length)
Truncates this string view by \a length characters.
Same as \c{*this = left(size() - length)}.
\note The behavior is undefined when \a length < 0 or \a length > size().
\sa mid(), left(), right(), chopped(), truncate()
*/
/*!
\fn QStringView QStringView::trimmed() const
Strips leading and trailing whitespace and returns the result.
Whitespace means any character for which QChar::isSpace() returns
\c true. This includes the ASCII characters '\\t', '\\n', '\\v',
'\\f', '\\r', and ' '.
*/
/*!
\fn int QStringView::compare(QStringView str, Qt::CaseSensitivity cs) const
\since 5.12
Returns an integer that compares to zero as this string-view compares to the
string-view \a str.
If \a cs is Qt::CaseSensitive (the default), the comparison is case sensitive;
otherwise the comparison is case-insensitive.
\sa operator==(), operator<(), operator>()
*/
/*!
\fn int QStringView::compare(QLatin1String l1, Qt::CaseSensitivity cs) const
\fn int QStringView::compare(QChar ch) const
\fn int QStringView::compare(QChar ch, Qt::CaseSensitivity cs) const
\since 5.15
Returns an integer that compares to zero as this string-view compares to the
Latin-1 string \a l1, or character \a ch, respectively.
If \a cs is Qt::CaseSensitive (the default), the comparison is case sensitive;
otherwise the comparison is case-insensitive.
\sa operator==(), operator<(), operator>()
*/
/*!
\fn QStringView::operator==(QStringView lhs, QStringView rhs)
\fn QStringView::operator!=(QStringView lhs, QStringView rhs)
\fn QStringView::operator< (QStringView lhs, QStringView rhs)
\fn QStringView::operator<=(QStringView lhs, QStringView rhs)
\fn QStringView::operator> (QStringView lhs, QStringView rhs)
\fn QStringView::operator>=(QStringView lhs, QStringView rhs)
Operators for comparing \a lhs to \a rhs.
\sa compare()
*/
/*!
\fn bool QStringView::startsWith(QStringView str, Qt::CaseSensitivity cs) const
\fn bool QStringView::startsWith(QLatin1String l1, Qt::CaseSensitivity cs) const
\fn bool QStringView::startsWith(QChar ch) const
\fn bool QStringView::startsWith(QChar ch, Qt::CaseSensitivity cs) const
Returns \c true if this string-view starts with string-view \a str,
Latin-1 string \a l1, or character \a ch, respectively;
otherwise returns \c false.
If \a cs is Qt::CaseSensitive (the default), the search is case-sensitive;
otherwise the search is case-insensitive.
\sa endsWith()
*/
/*!
\fn bool QStringView::endsWith(QStringView str, Qt::CaseSensitivity cs) const
\fn bool QStringView::endsWith(QLatin1String l1, Qt::CaseSensitivity cs) const
\fn bool QStringView::endsWith(QChar ch) const
\fn bool QStringView::endsWith(QChar ch, Qt::CaseSensitivity cs) const
Returns \c true if this string-view ends with string-view \a str,
Latin-1 string \a l1, or character \a ch, respectively;
otherwise returns \c false.
If \a cs is Qt::CaseSensitive (the default), the search is case-sensitive;
otherwise the search is case-insensitive.
\sa startsWith()
*/
/*!
\fn qsizetype QStringView::indexOf(QStringView str, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
\fn qsizetype QStringView::indexOf(QLatin1String l1, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
\fn qsizetype QStringView::indexOf(QChar c, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
\since 5.14
Returns the index position of the first occurrence of the string-view \a str,
Latin-1 string \a l1, or character \a ch, respectively, in this string-view,
searching forward from index position \a from. Returns -1 if \a str is not found.
If \a cs is Qt::CaseSensitive (default), the search is case
sensitive; otherwise the search is case insensitive.
If \a from is -1, the search starts at the last character; if it is
-2, at the next to last character and so on.
\sa QString::indexOf()
*/
/*!
\fn bool QStringView::contains(QStringView str, Qt::CaseSensitivity cs) const
\fn bool QStringView::contains(QLatin1String l1, Qt::CaseSensitivity cs) const
\fn bool QStringView::contains(QChar c, Qt::CaseSensitivity cs) const
\since 5.14
Returns \c true if this string-view contains an occurrence of the string-view
\a str, Latin-1 string \a l1, or character \a ch; otherwise returns \c false.
If \a cs is Qt::CaseSensitive (the default), the search is
case-sensitive; otherwise the search is case-insensitive.
\sa indexOf()
*/
/*!
\fn qsizetype QStringView::lastIndexOf(QStringView str, qsizetype from, Qt::CaseSensitivity cs) const
\fn qsizetype QStringView::lastIndexOf(QLatin1String l1, qsizetype from, Qt::CaseSensitivity cs) const
\fn qsizetype QStringView::lastIndexOf(QChar c, qsizetype from, Qt::CaseSensitivity cs) const
\since 5.14
Returns the index position of the last occurrence of the string-view \a str,
Latin-1 string \a l1, or character \a ch, respectively, in this string-view,
searching backward from index position \a from. If \a from is -1 (default),
the search starts at the last character; if \a from is -2, at the next to last
character and so on. Returns -1 if \a str is not found.
If \a cs is Qt::CaseSensitive (default), the search is case
sensitive; otherwise the search is case insensitive.
\sa QString::lastIndexOf()
*/
/*!
\fn QByteArray QStringView::toLatin1() const
Returns a Latin-1 representation of the string as a QByteArray.
The behavior is undefined if the string contains non-Latin1 characters.
\sa toUtf8(), toLocal8Bit(), QStringEncoder
*/
/*!
\fn QByteArray QStringView::toLocal8Bit() const
Returns a local 8-bit representation of the string as a QByteArray.
On Unix systems this is equivalen to toUtf8(), on Windows the systems
current code page is being used.
The behavior is undefined if the string contains characters not
supported by the locale's 8-bit encoding.
\sa toLatin1(), toUtf8(), QStringEncoder
*/
/*!
\fn QByteArray QStringView::toUtf8() const
Returns a UTF-8 representation of the string as a QByteArray.
UTF-8 is a Unicode codec and can represent all characters in a Unicode
string like QString.
\sa toLatin1(), toLocal8Bit(), QStringEncoder
*/
/*!
\fn QList<uint> QStringView::toUcs4() const
Returns a UCS-4/UTF-32 representation of the string as a QList<uint>.
UCS-4 is a Unicode codec and therefore it is lossless. All characters from
this string will be encoded in UCS-4. Any invalid sequence of code units in
this string is replaced by the Unicode replacement character
(QChar::ReplacementCharacter, which corresponds to \c{U+FFFD}).
The returned list is not 0-terminated.
\sa toUtf8(), toLatin1(), toLocal8Bit(), QStringEncoder
*/
/*!
\fn template <typename QStringLike> qToStringViewIgnoringNull(const QStringLike &s);
\since 5.10
\internal
Convert \a s to a QStringView ignoring \c{s.isNull()}.
Returns a string-view that references \a{s}' data, but is never null.
This is a faster way to convert a QString to a QStringView,
if null QStrings can legitimately be treated as empty ones.
\sa QString::isNull(), QStringView
*/
/*!
\fn bool QStringView::isRightToLeft() const
\since 5.11
Returns \c true if the string is read right to left.
\sa QString::isRightToLeft()
*/
/*!
\fn bool QStringView::isValidUtf16() const
\since 5.15
Returns \c true if the string contains valid UTF-16 encoded data,
or \c false otherwise.
Note that this function does not perform any special validation of the
data; it merely checks if it can be successfully decoded from UTF-16.
The data is assumed to be in host byte order; the presence of a BOM
is meaningless.
\sa QString::isValidUtf16()
*/
/*!
\fn QStringView::toWCharArray(wchar_t *array) const
\since 5.14
Transcribes this string into the given \a array.
The caller is responsible for ensuring \a array is large enough to hold the
\c wchar_t encoding of this string (allocating the array with the same length
as the string is always sufficient). The array is encoded in UTF-16 on
platforms where \c wchar_t is 2 bytes wide (e.g. Windows); otherwise (Unix
systems), \c wchar_t is assumed to be 4 bytes wide and the data is written
in UCS-4.
\note This function writes no null terminator to the end of \a array.
Returns the number of \c wchar_t entries written to \a array.
\sa QString::toWCharArray()
*/
/*!
\fn qsizetype QStringView::count(QChar ch, Qt::CaseSensitivity cs) const noexcept
\since 6.0
\overload count()
Returns the number of occurrences of the character \a ch in the
string reference.
If \a cs is Qt::CaseSensitive (default), the search is
case sensitive; otherwise the search is case insensitive.
\sa QString::count(), contains(), indexOf()
*/
/*!
\fn qsizetype QStringView::count(QStringView str, Qt::CaseSensitivity cs) const noexcept
\since 6.0
\overload count()
Returns the number of (potentially overlapping) occurrences of the
string reference \a str in this string reference.
If \a cs is Qt::CaseSensitive (default), the search is
case sensitive; otherwise the search is case insensitive.
\sa QString::count(), contains(), indexOf()
*/
/*!
\fn qint64 QStringView::toLongLong(bool *ok, int base) const
Returns the string converted to a \c{long long} using base \a
base, which is 10 by default and must be between 2 and 36, or 0.
Returns 0 if the conversion fails.
If \a ok is not \nullptr, failure is reported by setting *\a{ok}
to \c false, and success by setting *\a{ok} to \c true.
If \a base is 0, the C language convention is used: If the string
begins with "0x", base 16 is used; if the string begins with "0",
base 8 is used; otherwise, base 10 is used.
The string conversion will always happen in the 'C' locale. For locale
dependent conversion use QLocale::toLongLong()
\sa QString::toLongLong()
\since 6.0
*/
/*!
\fn quint64 QStringView::toULongLong(bool *ok, int base) const
Returns the string converted to an \c{unsigned long long} using base \a
base, which is 10 by default and must be between 2 and 36, or 0.
Returns 0 if the conversion fails.
If \a ok is not \nullptr, failure is reported by setting *\a{ok}
to \c false, and success by setting *\a{ok} to \c true.
If \a base is 0, the C language convention is used: If the string
begins with "0x", base 16 is used; if the string begins with "0",
base 8 is used; otherwise, base 10 is used.
The string conversion will always happen in the 'C' locale. For locale
dependent conversion use QLocale::toULongLong()
\sa QString::toULongLong()
\since 6.0
*/
/*!
\fn long QStringView::toLong(bool *ok, int base) const
Returns the string converted to a \c long using base \a
base, which is 10 by default and must be between 2 and 36, or 0.
Returns 0 if the conversion fails.
If \a ok is not \nullptr, failure is reported by setting *\a{ok}
to \c false, and success by setting *\a{ok} to \c true.
If \a base is 0, the C language convention is used: If the string
begins with "0x", base 16 is used; if the string begins with "0",
base 8 is used; otherwise, base 10 is used.
The string conversion will always happen in the 'C' locale. For locale
dependent conversion use QLocale::toLong()
\sa QString::toLong()
\since 6.0
*/
/*!
\fn ulong QStringView::toULong(bool *ok, int base) const
Returns the string converted to an \c{unsigned long} using base \a
base, which is 10 by default and must be between 2 and 36, or 0.
Returns 0 if the conversion fails.
If \a ok is not \nullptr, failure is reported by setting *\a{ok}
to \c false, and success by setting *\a{ok} to \c true.
If \a base is 0, the C language convention is used: If the string
begins with "0x", base 16 is used; if the string begins with "0",
base 8 is used; otherwise, base 10 is used.
The string conversion will always happen in the 'C' locale. For locale
dependent conversion use QLocale::toULongLong()
\sa QString::toULong()
\since 6.0
*/
/*!
\fn int QStringView::toInt(bool *ok, int base) const
Returns the string converted to an \c int using base \a
base, which is 10 by default and must be between 2 and 36, or 0.
Returns 0 if the conversion fails.
If \a ok is not \nullptr, failure is reported by setting *\a{ok}
to \c false, and success by setting *\a{ok} to \c true.
If \a base is 0, the C language convention is used: If the string
begins with "0x", base 16 is used; if the string begins with "0",
base 8 is used; otherwise, base 10 is used.
The string conversion will always happen in the 'C' locale. For locale
dependent conversion use QLocale::toInt()
\sa QString::toInt()
\since 6.0
*/
/*!
\fn uint QStringView::toUInt(bool *ok, int base) const
Returns the string converted to an \c{unsigned int} using base \a
base, which is 10 by default and must be between 2 and 36, or 0.
Returns 0 if the conversion fails.
If \a ok is not \nullptr, failure is reported by setting *\a{ok}
to \c false, and success by setting *\a{ok} to \c true.
If \a base is 0, the C language convention is used: If the string
begins with "0x", base 16 is used; if the string begins with "0",
base 8 is used; otherwise, base 10 is used.
The string conversion will always happen in the 'C' locale. For locale
dependent conversion use QLocale::toUInt()
\sa QString::toUInt()
\since 6.0
*/
/*!
\fn short QStringView::toShort(bool *ok, int base) const
Returns the string converted to a \c short using base \a
base, which is 10 by default and must be between 2 and 36, or 0.
Returns 0 if the conversion fails.
If \a ok is not \nullptr, failure is reported by setting *\a{ok}
to \c false, and success by setting *\a{ok} to \c true.
If \a base is 0, the C language convention is used: If the string
begins with "0x", base 16 is used; if the string begins with "0",
base 8 is used; otherwise, base 10 is used.
The string conversion will always happen in the 'C' locale. For locale
dependent conversion use QLocale::toShort()
\sa QString::toShort()
\since 6.0
*/
/*!
\fn ushort QStringView::toUShort(bool *ok, int base) const
Returns the string converted to an \c{unsigned short} using base \a
base, which is 10 by default and must be between 2 and 36, or 0.
Returns 0 if the conversion fails.
If \a ok is not \nullptr, failure is reported by setting *\a{ok}
to \c false, and success by setting *\a{ok} to \c true.
If \a base is 0, the C language convention is used: If the string
begins with "0x", base 16 is used; if the string begins with "0",
base 8 is used; otherwise, base 10 is used.
The string conversion will always happen in the 'C' locale. For locale
dependent conversion use QLocale::toUShort()
\sa QString::toUShort()
\since 6.0
*/
/*!
\fn double QStringView::toDouble(bool *ok) const
Returns the string converted to a \c double value.
Returns an infinity if the conversion overflows or 0.0 if the
conversion fails for other reasons (e.g. underflow).
If \a ok is not \nullptr, failure is reported by setting *\a{ok}
to \c false, and success by setting *\a{ok} to \c true.
The string conversion will always happen in the 'C' locale. For locale
dependent conversion use QLocale::toDouble()
For historic reasons, this function does not handle
thousands group separators. If you need to convert such numbers,
use QLocale::toDouble().
\sa QString::toDouble()
\since 6.0
*/
/*!
\fn float QStringView::toFloat(bool *ok) const
Returns the string converted to a \c float value.
Returns an infinity if the conversion overflows or 0.0 if the
conversion fails for other reasons (e.g. underflow).
If \a ok is not \nullptr, failure is reported by setting *\a{ok}
to \c false, and success by setting *\a{ok} to \c true.
The string conversion will always happen in the 'C' locale. For locale
dependent conversion use QLocale::toFloat()
\sa QString::toFloat()
\since 6.0
*/
/*!
\fn template <typename Needle, typename...Flags> auto QStringView::tokenize(Needle &&sep, Flags...flags) const
\fn template <typename Needle, typename...Flags> auto QLatin1String::tokenize(Needle &&sep, Flags...flags) const
\fn template <typename Needle, typename...Flags> auto QString::tokenize(Needle &&sep, Flags...flags) const &
\fn template <typename Needle, typename...Flags> auto QString::tokenize(Needle &&sep, Flags...flags) const &&
\fn template <typename Needle, typename...Flags> auto QString::tokenize(Needle &&sep, Flags...flags) &&
Splits the string into substring views wherever \a sep occurs, and
returns a lazy sequence of those strings.
Equivalent to
\code
return QStringTokenizer{std::forward<Needle>(sep), flags...};
\endcode
except it works without C++17 Class Template Argument Deduction (CTAD)
enabled in the compiler.
See QStringTokenizer for how \a sep and \a flags interact to form
the result.
\note While this function returns QStringTokenizer, you should never,
ever, name its template arguments explicitly. If you can use C++17 Class
Template Argument Deduction (CTAD), you may write
\code
QStringTokenizer result = sv.tokenize(sep);
\endcode
(without template arguments). If you can't use C++17 CTAD, you must store
the return value only in \c{auto} variables:
\code
auto result = sv.tokenize(sep);
\endcode
This is because the template arguments of QStringTokenizer have a very
subtle dependency on the specific tokenize() overload from which they are
returned, and they don't usually correspond to the type used for the separator.
\since 6.0
\sa QStringTokenizer, qTokenize()
*/
QT_END_NAMESPACE
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