RegionIndex now extends Iterable<Region>.

src/main/java/com/sk89q/worldguard/region/indices/FlatIndex.java

@@ -107,4 +107,9 @@ public synchronized int size() {
     public void reindex() {
         // Whoo, nothing to do, because this index is so simple
     }
+
+    @Override
+    public Iterator<Region> iterator() {
+        return regions.values().iterator();
+    }
 }

src/main/java/com/sk89q/worldguard/region/indices/PriorityRTreeIndex.java

@@ -132,4 +132,9 @@ public void reindex() {
         tree.load(regions.values());
     }
 
+    @Override
+    public Iterator<Region> iterator() {
+        return regions.values().iterator();
+    }
+
 }

src/main/java/com/sk89q/worldguard/region/indices/RegionIndex.java

@@ -38,7 +38,7 @@
  * querying by ID. Any casing can be used when looking up an ID. Implementations do NOT
  * have to be thread-safe.
  */
-public interface RegionIndex {
+public interface RegionIndex extends Iterable<Region> {
 
     /**
      * Queries the index for a list of {@link Region}s that contain the