declare swap generic (
   swapf when (float, float),
   swapc when (char, char));

swapf: proc (a, b);
   declare (a, b, t) float;
   t = a; a = b; b = t;
end swapf;
swapc: proc (a, b);
   declare (a, b) character(*);
   declare t character (length(b));
   t = a; a = b; b = t;
end swapc;

declare (r, s) character (5);
call swap (r, s);