function u=construct(s,sizes_in)
	u=mkunit(s);
	sz=s.sz; fn=s.fn;
	u.sizes_out = guess_sizes(fn,sz);
	u.process   = @proc;

	function out=proc, out=fn(sz); end
end

function sz_out=guess_sizes(fn,sz)
	out = fn(sz);
	sz_out = {size(out)};
end

