QtWidgets: replace some index-based for loops with C++11 range-for

This needs to be handled a bit carefully, because Qt containers
will detach upon being iteratoed over using range-for.

In the cases of this patch, that cannot happen, because all
containers are marked as const (either by this patch or before).

Separate patches will deal with other situations.

Apart from being more readable, range-for loops are also the
most efficient for loop.

This patch shaves almost 2K of text size off an optimized Linux
AMD64 GCC 4.9 build.

Change-Id: I53810c7b25420b4fd449d20c90c07503c5e76a66
Reviewed-by: Edward Welbourne <edward.welbourne@theqtcompany.com>
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/src/widgets/itemviews/qabstractitemview_p.h b/src/widgets/itemviews/qabstractitemview_p.h
index cb74586fab..2b28d8db84 100644
--- a/src/widgets/itemviews/qabstractitemview_p.h
+++ b/src/widgets/itemviews/qabstractitemview_p.h
@@ -177,9 +177,10 @@ public:
         // Whether the data can actually be dropped will be checked in drag move.
         if (event->type() == QEvent::DragEnter && (event->dropAction() & model->supportedDropActions())) {
             const QStringList modelTypes = model->mimeTypes();
-            for (int i = 0; i < modelTypes.count(); ++i)
-                if (mime->hasFormat(modelTypes.at(i)))
+            for (const auto &modelType : modelTypes) {
+                if (mime->hasFormat(modelType))
                     return true;
+            }
         }
 
         QModelIndex index;