[ox/std] Add is_pointer and is_pointer_v

(synced from 6610b501b3)

src/ox/std/typetraits.hpp

@@ -117,6 +117,19 @@ struct enable_if<true, T> {
 };
 
 
+template<typename T>
+struct is_pointer {
+	static constexpr bool value = false;
+};
+
+template<typename T>
+struct is_pointer<T*> {
+	static constexpr bool value = true;
+};
+
+template<typename T>
+constexpr bool is_pointer_v = is_pointer<T>::value;
+
 template<typename T>
 struct remove_pointer {
 	using type = T;