Call by reference: Was: Object orientation?

To reply to Yves Gauvreau question (Jan 24, 2001) about how to set values
within function, it is possible to do without without using the "<<-"
assignment operator or other nasty tricks. I had the same problem and I did
a nasty workaround two weeks ago implementing the functionality of reference
variables, but today I "ran into" the [R] help page for ".Alias". With
.Alias one can immitate call by reference! Here is an example that shows how
it works:

set <- function(object, value) {
  this <- .Alias(object);
  this$value <- value;
  return (invisible());
}