[i-love-flamingo#7]: comparing struct after injection with empty struct

dingo.go

@@ -381,11 +381,21 @@ func (injector *Injector) createInstanceOfAnnotatedType(t reflect.Type, annotati
 		subCircularTrace = append(subCircularTrace, circularTraceEntry{t, annotation})
 
 		n := reflect.New(t)
-		return n, injector.requestInjection(n.Interface(), subCircularTrace)
+		nInt := n.Interface()
+		err := injector.requestInjection(n.Interface(), subCircularTrace)
+		if reflect.DeepEqual(nInt, reflect.New(t).Interface()) {
+			return n, fmt.Errorf("element empty after injection. Might be caused by usage of struct instead of pointer receiver")
+		}
+		return n, err
 	}
 
 	n := reflect.New(t)
-	return n, injector.requestInjection(n.Interface(), nil)
+	nInt := n.Interface()
+	err := injector.requestInjection(nInt, nil)
+	if reflect.DeepEqual(nInt, reflect.New(t).Interface()) {
+		return n, fmt.Errorf("element empty after injection. Might be caused by usage of struct instead of pointer receiver")
+	}
+	return n, err
 }
 
 func reflectedError(err *error, t reflect.Type) reflect.Value {