// lists as [len, items...], items owned by the list
fn mklist(n) -> u
{
	var l = new(n + 1);
	l[0] = 0;
	return l as u;
}
fn push(m l, d item) { l[l[0] + 1] = item as d; l[0] = l[0] + 1; return 0; }
fn sum(m l) { var s = 0, i = 1; while (i <= l[0]) { s += l[i][0]; i++; } return s; }
fn box(v) -> u { var b = new(1); b[0] = v; return b as u; }
fn consume(d b) { return b[0]; }

fn main()
{
	var base = live_objects();
	{
		var l = mklist(8);		// u from mklist arrives here as m
		var i = 0;
		while (i < 5) {
			var b = box(i * 10);	// m in the loop body
			b as d;			// give it down
			push(l, b);
			i++;
		}
		putn(sum(l)); putc(' ');
		putn(live_objects() - base); putc(' ');	// list + 5 boxes
	}
	putn(live_objects() - base); putc(' ');	// freed at the block's end, children too

	// u handed up one block by assignment, and as a block value
	var outer;
	{
		var t = box(7);
		t as u;
		outer = t;
	}
	var v = { var w = box(8); w as u };
	putn(outer[0] + v[0]); putc(' ');

	// d given away to a callee
	var g = box(99);
	putn(consume(g as d)); putc(' ');

	// containers: child takes its parent's tag
	var p = new(2), c = new(1);
	c[0] = 5;
	p[0] = c;
	p[1] = new(3);
	putn(p[0][0]); putc(' ');
	putn(live_objects() - base); putc(10);
	return 0;
}