That is what FFI is for, right? Native structures do whatever they want. When gluing to C code, you use your FFI primitives to express the interfaces; and the structures which are expressed there are made to correspond to the C layout in some way.<p>You generally don&#x27;t want to be constraining how data structures work in a language so that they can be handed off to C code directly. (Unless perhaps you&#x27;re writing a language that is nearly a C dialect or something.)