OpenGL, PlatformSupport: 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.

While touching the code, also port loops to C++11 style.

Change-Id: Ib94d29b6ecec1cdab2604d0277a743e8b340be5e
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/src/platformsupport/input/evdevkeyboard/qevdevkeyboardmanager.cpp b/src/platformsupport/input/evdevkeyboard/qevdevkeyboardmanager.cpp
index 178578e5a2..ffe9f82325 100644
--- a/src/platformsupport/input/evdevkeyboard/qevdevkeyboardmanager.cpp
+++ b/src/platformsupport/input/evdevkeyboard/qevdevkeyboardmanager.cpp
@@ -135,9 +135,10 @@ void QEvdevKeyboardManager::loadKeymap(const QString &file)
         // Restore the default, which is either the built-in keymap or
         // the one given in the plugin spec.
         QString keymapFromSpec;
-        foreach (const QString &arg, m_spec.split(QLatin1Char(':'))) {
+        const auto specs = m_spec.splitRef(QLatin1Char(':'));
+        for (const QStringRef &arg : specs) {
             if (arg.startsWith(QLatin1String("keymap=")))
-                keymapFromSpec = arg.mid(7);
+                keymapFromSpec = arg.mid(7).toString();
         }
         foreach (QEvdevKeyboardHandler *handler, m_keyboards) {
             if (keymapFromSpec.isEmpty())