QString:add (last)indexOf overload with QRegularExpressionMatch output

This patch adds indexOf and lastIndexOf with QRegularExpressionMatch
output overloads to QString. This allows to get the match corresponding
to the index returned.

[ChangeLog][QtCore][QString] Added support for retrieving the
QRegularExpressionMatch to indexOf and lastIndexOf.

Change-Id: Ia0ae2d3ff78864c7053ffa397874aca1d2b1c35c
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

3 files changed, 69 insertions, 5 deletions

diff --git a/src/corelib/doc/snippets/qstring/main.cpp b/src/corelib/doc/snippets/qstring/main.cpp
index bf45a31c29..f5c6b69695 100644
--- a/src/corelib/doc/snippets/qstring/main.cpp
+++ b/src/corelib/doc/snippets/qstring/main.cpp
@@ -394,6 +394,13 @@ void Widget::firstIndexOfFunction()
     QString str = "the minimum";
     str.indexOf(QRegularExpression("m[aeiou]"), 0);       // returns 4
     //! [93]
+
+    //! [97]
+    QString str = "the minimum";
+    QRegularExpressionMatch match;
+    str.indexOf(QRegularExpression("m[aeiou]"), 0, &match);       // returns 4
+    // match.captured() == mi
+    //! [97]
 }
 
 void Widget::insertFunction()
@@ -444,6 +451,13 @@ void Widget::lastIndexOfFunction()
     QString str = "the minimum";
     str.lastIndexOf(QRegularExpression("m[aeiou]"));      // returns 8
     //! [94]
+
+    //! [98]
+    QString str = "the minimum";
+    QRegularExpressionMatch match;
+    str.lastIndexOf(QRegularExpression("m[aeiou]"), -1, &match);      // returns 8
+    // match.captured() == mu
+    //! [98]
 }
 
 void Widget::leftFunction()
diff --git a/src/corelib/tools/qstring.cpp b/src/corelib/tools/qstring.cpp
index 169b48aa5a..5454a8fe4d 100644
--- a/src/corelib/tools/qstring.cpp
+++ b/src/corelib/tools/qstring.cpp
@@ -3677,14 +3677,39 @@ int QString::count(const QRegExp& rx) const
 */
 int QString::indexOf(const QRegularExpression& re, int from) const
 {
+    return indexOf(re, from, Q_NULLPTR);
+}
+
+/*!
+    \overload
+    \since 5.5
+
+    Returns the index position of the first match of the regular
+    expression \a re in the string, searching forward from index
+    position \a from. Returns -1 if \a re didn't match anywhere.
+
+    If the match is successful and \a rmatch is not a null pointer, it also
+    writes the results of the match into the QRegularExpressionMatch object
+    pointed to by \a rmatch.
+
+    Example:
+
+    \snippet qstring/main.cpp 97
+*/
+int QString::indexOf(const QRegularExpression &re, int from, QRegularExpressionMatch *rmatch) const
+{
     if (!re.isValid()) {
         qWarning("QString::indexOf: invalid QRegularExpression object");
         return -1;
     }
 
     QRegularExpressionMatch match = re.match(*this, from);
-    if (match.hasMatch())
-        return match.capturedStart();
+    if (match.hasMatch()) {
+        const int ret = match.capturedStart();
+        if (rmatch)
+            *rmatch = qMove(match);
+        return ret;
+    }
 
     return -1;
 }
@@ -3703,22 +3728,45 @@ int QString::indexOf(const QRegularExpression& re, int from) const
 */
 int QString::lastIndexOf(const QRegularExpression &re, int from) const
 {
+    return lastIndexOf(re, from, Q_NULLPTR);
+}
+
+/*!
+    \overload
+    \since 5.5
+
+    Returns the index position of the last match of the regular
+    expression \a re in the string, which starts before the index
+    position \a from. Returns -1 if \a re didn't match anywhere.
+
+    If the match is successful and \a rmatch is not a null pointer, it also
+    writes the results of the match into the QRegularExpressionMatch object
+    pointed to by \a rmatch.
+
+    Example:
+
+    \snippet qstring/main.cpp 98
+*/
+int QString::lastIndexOf(const QRegularExpression &re, int from, QRegularExpressionMatch *rmatch) const
+{
     if (!re.isValid()) {
         qWarning("QString::lastIndexOf: invalid QRegularExpression object");
         return -1;
     }
 
     int endpos = (from < 0) ? (size() + from + 1) : (from + 1);
-
     QRegularExpressionMatchIterator iterator = re.globalMatch(*this);
     int lastIndex = -1;
     while (iterator.hasNext()) {
         QRegularExpressionMatch match = iterator.next();
         int start = match.capturedStart();
-        if (start < endpos)
+        if (start < endpos) {
             lastIndex = start;
-        else
+            if (rmatch)
+                *rmatch = qMove(match);
+        } else {
             break;
+        }
     }
 
     return lastIndex;
diff --git a/src/corelib/tools/qstring.h b/src/corelib/tools/qstring.h
index a6e13e37b5..dee76ceedd 100644
--- a/src/corelib/tools/qstring.h
+++ b/src/corelib/tools/qstring.h
@@ -335,7 +335,9 @@ public:
 
 #ifndef QT_NO_REGULAREXPRESSION
     int indexOf(const QRegularExpression &re, int from = 0) const;
+    int indexOf(const QRegularExpression &re, int from, QRegularExpressionMatch *rmatch) const; // ### Qt 6: merge overloads
     int lastIndexOf(const QRegularExpression &re, int from = -1) const;
+    int lastIndexOf(const QRegularExpression &re, int from, QRegularExpressionMatch *rmatch) const; // ### Qt 6: merge overloads
     bool contains(const QRegularExpression &re) const;
     bool contains(const QRegularExpression &re, QRegularExpressionMatch *match) const; // ### Qt 6: merge overloads
     int count(const QRegularExpression &re) const;