sizeof(foo) does not work, where foo is a variable of polymorphic type.

[pabuhr]

sizeof(foo) does not work, where foo is a variable of polymorphic type.
Uses sizeof(void*) instead, since foo is represented as one.

forall(otype T)
void print_sizealign(T dummy) {
    printf("size:%lu, align:%lu\n", sizeof(T), __alignof(T)); // correct
    printf("size:%lu, align:%lu\n", sizeof(dummy), __alignof(dummy)); // fails (unless T has same size/align as void*)
}