samer@0: function u=construct(s,sizes_in)
samer@0: 	u=mkunit(s);
samer@0: 	fn=s.fn(sizes_in);
samer@0: 	if isempty(s.sizefn) 
samer@0: 		u.sizes_out=guess_sizes(fn,sizes_in,nargout(s));
samer@0: 	else 
samer@0: 		u.sizes_out=s.sizefn(sizes_in);
samer@0: 	end
samer@0: 	u.process=mkproc(fn,nargin(s),nargout(s));
samer@0: 
samer@0: end
samer@0: 
samer@0: function f=mkproc(fn,nin,nout);
samer@0: 	if     nout==0, f = @proc_n0;
samer@0: 	elseif nin==0,  f = @proc_0n;
samer@0: 	elseif nin==1 && nout==1, f=@proc_11;
samer@0: 	else f=@proc_nn; end
samer@0: 
samer@0: 	function proc_n0(varargin), fn(varargin{1:nin}); end
samer@0: 	function out=proc_11(in), out=fn(in); end
samer@0: 	function varargout=proc_0n, [varargout{1:nout}]=fn(); end
samer@0: 	function varargout=proc_nn(varargin), 
samer@0: 		[varargout{1:nout}]=fn(varargin{1:nin}); 
samer@0: 	end
samer@0: end
samer@0: 
samer@0: function sz_out=guess_sizes(fn,sz_in,nout)
samer@0: 	ins = map(@zeros,sz_in);
samer@0: 	[outs{1:nout}] = fn(ins{:});
samer@0: 	sz_out = map(@size,outs);
samer@0: end
samer@0: