Widgets: use QStringRef to optimize memory allocation

Replace substring functions that return QString with
corresponding functions that return QStringRef where
it's possible.

Create QString from QStringRef only where necessary.

Change-Id: Id1c39093199519f2794b11560c2c0ded2d52b928
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/widgets/widgets/qlineedit_p.cpp b/src/widgets/widgets/qlineedit_p.cpp
index 6ff40e9c50..3d8a854753 100644
--- a/src/widgets/widgets/qlineedit_p.cpp
+++ b/src/widgets/widgets/qlineedit_p.cpp
@@ -97,7 +97,7 @@ void QLineEditPrivate::_q_completionHighlighted(const QString &newText)
     } else {
         int c = control->cursor();
         QString text = control->text();
-        q->setText(text.left(c) + newText.mid(c));
+        q->setText(text.leftRef(c) + newText.midRef(c));
         control->moveCursor(control->end(), false);
 #ifndef Q_OS_ANDROID
         const bool mark = true;