Structs cannot escape the function they are defined in

[Champii]

Structs are built using alloca statements and thus are deallocated when the function returns.
This is obviously UB and should be mitigated by allocating them on the heap.
This would require either to allow for explicit heap allocation/deallocation like new/free or to have a proper lifetime checker to transparently do these operations.

[Champii]

This has been implemented in #179 but only the allocation part.
Will need #180 to properly deallocate