That is of course fine, with the drawback that it requires a public definition of the foo type. I would write the allocation as foo * const g = malloc(siz

That is of course fine, with the drawback that it requires a public definition of the foo type. I would write the allocation as foo * const g = malloc(sizeof *g); to avoid repeating the type name and "lock" the allocation to the variable. If the type on the left hand side ever would change, this still does the right thing.