So, we know the standard representation of a sum type is:
struct _uctor_ { int variant; void *data; };
which is layout compatible with
int * address
however there are various special representations. For example
if a variant has no argument, it's just represented by the "int" ta
Now I have unions appearing to work so that a union of
one constructor is replaced by its argument. Eg
union X = | R of int
is replaced by int. This is still not fully efficient, since you still need
to use a match to extract the value:
let R ?r = x in ...l
and the match still u
