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, 7 insertions, 8 deletions

diff --git a/src/widgets/dialogs/qmessagebox.cpp b/src/widgets/dialogs/qmessagebox.cpp
index 76a9de0f1c..704883b5c6 100644
--- a/src/widgets/dialogs/qmessagebox.cpp
+++ b/src/widgets/dialogs/qmessagebox.cpp
@@ -1047,26 +1047,26 @@ void QMessageBoxPrivate::detectEscapeButton()
     }
 
     // if the message box has one RejectRole button, make it the escape button
-    for (int i = 0; i < buttons.count(); i++) {
-        if (buttonBox->buttonRole(buttons.at(i)) == QDialogButtonBox::RejectRole) {
+    for (auto *button : buttons) {
+        if (buttonBox->buttonRole(button) == QDialogButtonBox::RejectRole) {
             if (detectedEscapeButton) { // already detected!
                 detectedEscapeButton = 0;
                 break;
             }
-            detectedEscapeButton = buttons.at(i);
+            detectedEscapeButton = button;
         }
     }
     if (detectedEscapeButton)
         return;
 
     // if the message box has one NoRole button, make it the escape button
-    for (int i = 0; i < buttons.count(); i++) {
-        if (buttonBox->buttonRole(buttons.at(i)) == QDialogButtonBox::NoRole) {
+    for (auto *button : buttons) {
+        if (buttonBox->buttonRole(button) == QDialogButtonBox::NoRole) {
             if (detectedEscapeButton) { // already detected!
                 detectedEscapeButton = 0;
                 break;
             }
-            detectedEscapeButton = buttons.at(i);
+            detectedEscapeButton = button;
         }
     }
 }
@@ -1506,8 +1506,7 @@ void QMessageBox::keyPressEvent(QKeyEvent *e)
         int key = e->key() & ~Qt::MODIFIER_MASK;
         if (key) {
             const QList<QAbstractButton *> buttons = d->buttonBox->buttons();
-            for (int i = 0; i < buttons.count(); ++i) {
-                QAbstractButton *pb = buttons.at(i);
+            for (auto *pb : buttons) {
                 QKeySequence shortcut = pb->shortcut();
                 if (!shortcut.isEmpty() && key == int(shortcut[0] & ~Qt::MODIFIER_MASK)) {
                     pb->animateClick();