12.9: adda/translate/passing destination references implicitely:
. by passing destination locations as references
instead of having functions return objects,
we can avoid a lot of garbage generation,
but the reason oop doesn't do this is it complicates the job of
application programmers .
. the reason addx does do this, is it has a translator
that does this automatically for programmers:
the compiler is looking for their y`= f(x)
and converting it for them into f-proc(&y, x).
. I think I had a contradictory example somewhere,
but it only applies to when the library programmer is
wanting to do systems programming (when it extends the compiler).