Add rvalue-ref qualified {QString,QByteArray}::{simplified,trimmed}

Of the const overloads that return a QString or a QByteArray, this is
one that gains the most benefit. It happens often in constructs like:

    QByteArray s = x.readLine().trimmed();

After this change, 41 out of 103 calls to trimmed become rvalue in Qt
and 272 out of 441 in Qt Creator. For simplified, the numbers are 27 out
of 69 in Qt and 10 out of 19 in Qt Creator.

Other candidates are left, right, and mid, but there are exactly zero
uses of left, right and mid on an xvalue QString or QByteArray in Qt.

I'm being lazy and using qstring_compat.cpp to store the QByteArray
compat methods.

Change-Id: I4e410fc1adc4c761bb07cc3d43b348a65befa9f6
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

1 files changed, 19 insertions, 4 deletions

diff --git a/src/corelib/tools/qbytearray.cpp b/src/corelib/tools/qbytearray.cpp
index f57bcdb424..625b78d001 100644
--- a/src/corelib/tools/qbytearray.cpp
+++ b/src/corelib/tools/qbytearray.cpp
@@ -3196,6 +3196,8 @@ QDataStream &operator>>(QDataStream &in, QByteArray &ba)
 */
 
 /*!
+    \fn QByteArray QByteArray::simplified() const
+
     Returns a byte array that has whitespace removed from the start
     and the end, and which has each sequence of internal whitespace
     replaced with a single space.
@@ -3209,12 +3211,19 @@ QDataStream &operator>>(QDataStream &in, QByteArray &ba)
 
     \sa trimmed()
 */
-QByteArray QByteArray::simplified() const
+QByteArray QByteArray::simplified_helper(const QByteArray &a)
 {
-    return QStringAlgorithms<const QByteArray>::simplified_helper(*this);
+    return QStringAlgorithms<const QByteArray>::simplified_helper(a);
+}
+
+QByteArray QByteArray::simplified_helper(QByteArray &a)
+{
+    return QStringAlgorithms<QByteArray>::simplified_helper(a);
 }
 
 /*!
+    \fn QByteArray QByteArray::trimmed() const
+
     Returns a byte array that has whitespace removed from the start
     and the end.
 
@@ -3229,11 +3238,17 @@ QByteArray QByteArray::simplified() const
 
     \sa simplified()
 */
-QByteArray QByteArray::trimmed() const
+QByteArray QByteArray::trimmed_helper(const QByteArray &a)
 {
-    return QStringAlgorithms<const QByteArray>::trimmed_helper(*this);
+    return QStringAlgorithms<const QByteArray>::trimmed_helper(a);
 }
 
+QByteArray QByteArray::trimmed_helper(QByteArray &a)
+{
+    return QStringAlgorithms<QByteArray>::trimmed_helper(a);
+}
+
+
 /*!
     Returns a byte array of size \a width that contains this byte
     array padded by the \a fill character.