@define consume1(g)
{
	@local x;

	x = g();
	if(x != nil)
		printf("guardian returned %a\n", x);
	else
		printf("guardian is empty\n");
	return x;
}

g = mkguardian();
s = "abc";
g(s);
g(s);
g([1,2,3]);
consume1(g);
s = nil;
gc(0,0);

while(consume1(g) != nil)
	;