QTimeZone: don't iterate over QHash::keys()

... iterate over the hash directly.

Prevents hash lookups and the creation of a temporary QList.

Saves over 376b in text size on optimized GCC 4.9 Linux
AMD64 builds.

Change-Id: I7f1a22da33b94bc91bec89f62c471f8279a5d702
Reviewed-by: Sérgio Martins <iamsergio@gmail.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/src/corelib/tools/qtimezoneprivate_tz.cpp b/src/corelib/tools/qtimezoneprivate_tz.cpp
index 85ed345869..4bb52a8d8a 100644
--- a/src/corelib/tools/qtimezoneprivate_tz.cpp
+++ b/src/corelib/tools/qtimezoneprivate_tz.cpp
@@ -983,9 +983,9 @@ QList<QByteArray> QTzTimeZonePrivate::availableTimeZoneIds(QLocale::Country coun
 {
     // TODO AnyCountry
     QList<QByteArray> result;
-    foreach (const QByteArray &key, tzZones->keys()) {
-        if (tzZones->value(key).country == country)
-            result << key;
+    for (auto it = tzZones->cbegin(), end = tzZones->cend(); it != end; ++it) {
+        if (it.value().country == country)
+            result << it.key();
     }
     std::sort(result.begin(), result.end());
     return result;