Incompatibilities with PHP 5.6 and HHVM fixed

Author: remorhaz

src/Pointer/Evaluate/AdvancerIndex.php

@@ -26,7 +26,10 @@ public function advance()
 
     public function write($data)
     {
-        $this->getCursor()->getData()[$this->getKey()] = $data;
+        $cursorData = &$this
+            ->getCursor()
+            ->getData();
+        $cursorData[$this->getKey()] = $data;
         return $this;
     }
 

src/Pointer/Evaluate/AdvancerNextIndex.php

@@ -20,9 +20,10 @@ public function advance()
 
     public function write($data)
     {
-        $this
+        $cursorData = &$this
             ->getCursor()
-            ->getData()[] = $data;
+            ->getData();
+        $cursorData[] = $data;
         return $this;
     }