CoreLib: 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: Id9ea11b16947220cd27787c0b529de62d10b6c26
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

1 files changed, 4 insertions, 4 deletions

diff --git a/src/corelib/plugin/qlibrary.cpp b/src/corelib/plugin/qlibrary.cpp
index f7e57461e3..886dd20d0e 100644
--- a/src/corelib/plugin/qlibrary.cpp
+++ b/src/corelib/plugin/qlibrary.cpp
@@ -616,12 +616,12 @@ bool QLibrary::isLibrary(const QString &fileName)
     QString completeSuffix = QFileInfo(fileName).completeSuffix();
     if (completeSuffix.isEmpty())
         return false;
-    QStringList suffixes = completeSuffix.split(QLatin1Char('.'));
+    const QVector<QStringRef> suffixes = completeSuffix.splitRef(QLatin1Char('.'));
 # if defined(Q_OS_DARWIN)
 
     // On Mac, libs look like libmylib.1.0.0.dylib
-    const QString lastSuffix = suffixes.at(suffixes.count() - 1);
-    const QString firstSuffix = suffixes.at(0);
+    const QStringRef &lastSuffix = suffixes.at(suffixes.count() - 1);
+    const QStringRef &firstSuffix = suffixes.at(0);
 
     bool valid = (lastSuffix == QLatin1String("dylib")
             || firstSuffix == QLatin1String("so")
@@ -657,7 +657,7 @@ bool QLibrary::isLibrary(const QString &fileName)
     int suffix;
     int suffixPos = -1;
     for (suffix = 0; suffix < validSuffixList.count() && suffixPos == -1; ++suffix)
-        suffixPos = suffixes.indexOf(validSuffixList.at(suffix));
+        suffixPos = suffixes.indexOf(QStringRef(&validSuffixList.at(suffix)));
 
     bool valid = suffixPos != -1;
     for (int i = suffixPos + 1; i < suffixes.count() && valid; ++i)