check if collection is empty without loading it

Actually isEmpty() is always loading the collection in LazyCriteriaCollection.
A lazy version should use the existing functionality of count() to check if there are no elements if the collection is not initialized.

lib/Doctrine/ORM/LazyCriteriaCollection.php

@@ -82,6 +82,20 @@ class LazyCriteriaCollection extends AbstractLazyCollection implements Selectabl
         return $this->count = $this->entityPersister->count($this->criteria);
     }
 
+    /**
+     * check if collection is empty without loading it
+     *
+     * @return boolean TRUE if the collection is empty, FALSE otherwise.
+     */
+    public function isEmpty()
+    {
+        if ($this->isInitialized()) {
+            return $this->collection->isEmpty();
+        }
+
+        return $this->count() == 0;
+    }
+
     /**
      * Do an optimized search of an element
      *