// expect: 0 1 2 2 0/
// destructors 6.15.3: two unreachable values with drops that reach each other are finalized one per collection (each is in a cycle, so nothing outside it drops first), each exactly once, then freed
include rt;
int n;
word g;
struct node { node* other; int v; void drop() { n++; } }
unchecked fn make() {
	node* a = rt.new(node); node* b = rt.new(node);
	a.v = 1; b.v = 2; a.other = b; b.other = a;
	g = a;
	return 0;
}
fn main() {
	make();
	rt.gc(); rt.put_n(n); rt.put_c(32);
	g = 0;
	rt.gc(); rt.put_n(n); rt.put_c(32);
	rt.gc(); rt.put_n(n); rt.put_c(32);
	rt.gc(); rt.gc(); rt.put_n(n); rt.put_c(32);
	rt.put_n(rt.dcount); rt.put_c(10);	// both entries are gone with their blocks
	return 0;
}
// zc0: skip