[boost] Re: Fixed-Point Decimal Proposal

From: Bill Seymour (bill-at-the-office_at_[hidden])
Date: 2002-03-11 13:44:35

Jeff wrote:
>
> I'm asking you to re-examine the basic design decision
> that associates the rounding mode with the operation
> instead of the type.  While I agree from a theoretical
> sense that this is correct I don't see the advantage
> to the user.  ... I have worked on applications where
> the 'type centric' approach would have been useful.
> I haven't worked on any applications where I would need
> the rounding mode by operation feature.
>

My design decision was sort of _a priori_; and I can't
give any examples from real code in which it would be
preferable; so I'll have to admit that you're right
unless somebody else comes to my defense.  8-)

The question is:  should the rounding mode bind to
the operation or to the operand?

If the latter, should it be a compile-time mechanism
(one obvious implementation being a template parameter
that specifies a rounding policy, thus making the
rounding mode a part of the type) or a run-time
mechanism (perhaps a mutable pointer to a rounding
mode and a member function for changing it)?

I'll be happy to go with the flow.

--Bill Seymour