Add some missing QStringView overloads to QString

These are added to aid writing portable code between
Qt 5.15 and Qt 6.

[ChangeLog][QtCore][QStringView] A couple of methods have been
added to QStringView that make it easier to write code that is
portable between Qt 5.15 and Qt 6. Those include
QStringView::split(), QStringView::count(), number conversion
methods (QStringView::toInt() and friends). A couple of overloads
taking QStringView have been added to QRegularExpression (match()
and globalMatch()) and QString (append(), prepend(), insert() and
localeAwareCompare()).

Fixes: QTBUG-86516
Change-Id: I98779217c7a4107fbe086f956d24b1ce059194d7
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 95 insertions, 0 deletions

diff --git a/src/corelib/text/qstring.cpp b/src/corelib/text/qstring.cpp
index 150d40c12c..f9ec7678fe 100644
--- a/src/corelib/text/qstring.cpp
+++ b/src/corelib/text/qstring.cpp
@@ -2533,6 +2533,21 @@ QString &QString::operator=(QChar ch)
     first extended using resize().
 */
 
+/*!
+    \fn QString& QString::insert(int position, QStringView str)
+    \since 5.15.2
+    \overload insert()
+
+    Inserts the string reference \a str at the given index \a position and
+    returns a reference to this string.
+
+    If the given \a position is greater than size(), the array is
+    first extended using resize().
+
+    \note This method has been added in 5.15.2 to simplify writing code that is portable
+    between Qt 5.15 and Qt 6.
+*/
+
 
 /*!
     \fn QString& QString::insert(int position, const char *str)
@@ -2797,6 +2812,16 @@ QString &QString::append(QChar ch)
     returns a reference to this string.
 */
 
+/*!
+    \fn QString &QString::prepend(QStringView str)
+    \since 5.15.2
+
+    Prepends the given string \a str to this string and returns the result.
+
+    \note This method has been added in 5.15.2 to simplify writing code that is portable
+    between Qt 5.15 and Qt 6.
+*/
+
 /*! \fn QString &QString::prepend(const QByteArray &ba)
 
     \overload prepend()
@@ -6069,6 +6094,16 @@ QString& QString::fill(QChar ch, int size)
     Appends the string section referenced by \a str to this string.
 */
 
+/*! \fn QString &QString::operator+=(QStringView str)
+    \since 5.15.2
+    \overload operator+=()
+
+    Appends the string section referenced by \a str to this string.
+
+    \note This method has been added in 5.15.2 to simplify writing code that is portable
+    between Qt 5.15 and Qt 6.
+*/
+
 /*! \fn QString &QString::operator+=(char ch)
 
     \overload operator+=()
@@ -6395,6 +6430,27 @@ int QString::compare_helper(const QChar *data1, int length1, QLatin1String s2,
 */
 
 /*!
+    \fn int QString::localeAwareCompare(QStringView other) const
+    \since 5.15.2
+    \overload localeAwareCompare()
+
+    Compares this string with the \a other string and returns an
+    integer less than, equal to, or greater than zero if this string
+    is less than, equal to, or greater than the \a other string.
+
+    The comparison is performed in a locale- and also
+    platform-dependent manner. Use this function to present sorted
+    lists of strings to the user.
+
+    Same as \c {localeAwareCompare(*this, other)}.
+
+    \note This method has been added in 5.15.2 to simplify writing code that is portable
+    between Qt 5.15 and Qt 6.
+
+    \sa {Comparing Strings}
+*/
+
+/*!
     \fn int QString::localeAwareCompare(const QString &s1, const QStringRef &s2)
     \since 4.5
     \overload localeAwareCompare()
@@ -6410,6 +6466,24 @@ int QString::compare_helper(const QChar *data1, int length1, QLatin1String s2,
     \sa {Comparing Strings}
 */
 
+/*!
+    \fn int QString::localeAwareCompare(QStringView s1, QStringView s2)
+    \since 5.15.2
+    \overload localeAwareCompare()
+
+    Compares \a s1 with \a s2 and returns an integer less than, equal
+    to, or greater than zero if \a s1 is less than, equal to, or
+    greater than \a s2.
+
+    The comparison is performed in a locale- and also
+    platform-dependent manner. Use this function to present sorted
+    lists of strings to the user.
+
+    \note This method has been added in 5.15.2 to simplify writing code that is portable
+    between Qt 5.15 and Qt 6.
+
+    \sa {Comparing Strings}
+*/
 
 #if !defined(CSTR_LESS_THAN)
 #define CSTR_LESS_THAN    1
@@ -11168,6 +11242,16 @@ QString &QString::append(const QStringRef &str)
 }
 
 /*!
+    \fn QString &QString::append(QStringView str)
+    \since 5.15.2
+
+    Appends the given string \a str to this string and returns the result.
+
+    \note This method has been added in 5.15.2 to simplify writing code that is portable
+    between Qt 5.15 and Qt 6.
+*/
+
+/*!
     \fn QStringRef::left(int n) const
     \since 5.2
 
diff --git a/src/corelib/text/qstring.h b/src/corelib/text/qstring.h
index 7906aeaffc..5a4ac497e0 100644
--- a/src/corelib/text/qstring.h
+++ b/src/corelib/text/qstring.h
@@ -541,17 +541,21 @@ public:
     QString &insert(int i, const QChar *uc, int len);
     inline QString &insert(int i, const QString &s) { return insert(i, s.constData(), s.length()); }
     inline QString &insert(int i, const QStringRef &s);
+    inline QString &insert(int i, QStringView s)
+    { return insert(i, s.data(), s.length()); }
     QString &insert(int i, QLatin1String s);
     QString &append(QChar c);
     QString &append(const QChar *uc, int len);
     QString &append(const QString &s);
     QString &append(const QStringRef &s);
     QString &append(QLatin1String s);
+    inline QString &append(QStringView s) { return append(s.data(), s.length()); }
     inline QString &prepend(QChar c) { return insert(0, c); }
     inline QString &prepend(const QChar *uc, int len) { return insert(0, uc, len); }
     inline QString &prepend(const QString &s) { return insert(0, s); }
     inline QString &prepend(const QStringRef &s) { return insert(0, s); }
     inline QString &prepend(QLatin1String s) { return insert(0, s); }
+    inline QString &prepend(QStringView s) { return insert(0, s); }
 
     inline QString &operator+=(QChar c) {
         if (d->ref.isShared() || uint(d->size) + 2u > d->alloc)
@@ -565,6 +569,7 @@ public:
     inline QString &operator+=(const QString &s) { return append(s); }
     inline QString &operator+=(const QStringRef &s) { return append(s); }
     inline QString &operator+=(QLatin1String s) { return append(s); }
+    inline QString &operator+=(QStringView s) { return append(s); }
 
     QString &remove(int i, int len);
     QString &remove(QChar c, Qt::CaseSensitivity cs = Qt::CaseSensitive);
@@ -1780,8 +1785,10 @@ public:
 
     int localeAwareCompare(const QString &s) const;
     int localeAwareCompare(const QStringRef &s) const;
+    int localeAwareCompare(QStringView str) const;
     static int localeAwareCompare(const QStringRef &s1, const QString &s2);
     static int localeAwareCompare(const QStringRef &s1, const QStringRef &s2);
+    static int localeAwareCompare(QStringView s1, QStringView s2);
 
     Q_REQUIRED_RESULT QStringRef trimmed() const;
     short  toShort(bool *ok = nullptr, int base = 10) const;
@@ -2016,10 +2023,14 @@ inline int QStringRef::localeAwareCompare(const QString &s) const
 { return QString::localeAwareCompare_helper(constData(), length(), s.constData(), s.length()); }
 inline int QStringRef::localeAwareCompare(const QStringRef &s) const
 { return QString::localeAwareCompare_helper(constData(), length(), s.constData(), s.length()); }
+inline int QStringRef::localeAwareCompare(QStringView s) const
+{ return QString::localeAwareCompare_helper(constData(), length(), s.data(), s.size()); }
 inline int QStringRef::localeAwareCompare(const QStringRef &s1, const QString &s2)
 { return QString::localeAwareCompare_helper(s1.constData(), s1.length(), s2.constData(), s2.length()); }
 inline int QStringRef::localeAwareCompare(const QStringRef &s1, const QStringRef &s2)
 { return QString::localeAwareCompare_helper(s1.constData(), s1.length(), s2.constData(), s2.length()); }
+inline int QStringRef::localeAwareCompare(QStringView s1, QStringView s2)
+{ return QString::localeAwareCompare_helper(s1.data(), s1.size(), s2.data(), s2.size()); }
 
 #if QT_STRINGVIEW_LEVEL < 2
 inline bool QStringRef::contains(const QString &s, Qt::CaseSensitivity cs) const