Limit concat to non pointer types to avoid hard to track problems

include/PSX/GPU/Primitives/linked_elements.hpp

@@ -1,5 +1,6 @@
 #pragma once
 #include "../../Auxiliary/bits.hpp"
+#include "../../Auxiliary/type_traits.hpp"
 
 namespace JabyEngine {
     namespace GPU {
@@ -37,13 +38,13 @@ namespace JabyEngine {
             }
 
             template<typename T>
-            T& concat(T& obj) {
+            enable_if<!is_pointer<T>::value, T&>::type concat(T& obj) {
                 Link::set_adr(&obj);
                 return obj;
             }
 
             template<typename T>
-            const T& concat(const T& obj) {
+            enable_if<!is_pointer<T>::value, const T&>::type concat(const T& obj) {
                 return concat(const_cast<T&>(obj));
             }