Re: Dimensions and fixed point types

[Duncan Sands <baldrick@free.fr>]

On Friday 11 June 2004 19:47, Hyman Rosen wrote:
> Duncan Sands wrote:
> > On Friday 11 June 2004 09:26, Hyman Rosen wrote:
> >>You appear to imply that multiplying apples and apples
> >>to get apples, on the other hand, *is* "type safe". Why?
> > 
> > I implied no such thing.
> 
> Well, here's what you said:
>     > It seems to me that a much better approach would be
>     > to say that multiplication between different fixed
>     > point types is NOT automatically defined
> 
> This certainly implies that you believe that multiplication
> of a fixed point type with itself should be automatically
> defined. How else is one to read this?

There is no contradiction.  Not saying X is not the same
as saying not X.  However from a practical point of view,
any proposal to not have multiplication be auto-defined
between fixed point numbers of the same type would
never be accepted, since such multiplication is defined
in the case of integer and floating point types.  So I didn't
propose it.  That doesn't mean I think that auto-defining
such multiplication is a good idea.  In many contexts
multiplying two numbers of the same type makes no sense.

Ciao,

Duncan.