From: Jeff Garland (jeff_at_[hidden])
Date: 2002-08-30 22:06:11
> Bill's proposal is excellent. Obviously much thought, work and detail went
> into his fixed decimal class and I'd love to borrow ideas. I don't have any
> formal proposal yet as I'm still bouncing around ideas.
Well, here's one to bounce. Suppose we decide that Bill's proposal defines
the desired interface for fixed_decimals. Perhaps your implementation
idea, which seems to have potential, could be dropped into the current
However, just scanning Bill's new proposal, it looks like you are going back
to a proposal he has already rejected, that is 'scale' is fixed at
> The basis of the fixed class I propose is that the fixed point number is
> represented by a single integer variable that can be signed or unsigned, of
> any legal integer size. The class will allow for an arbitrary number of
> bits to be assigned to the integer portion of the fixed point number from
> zero up to an including all the bits in the integer. By keeping the fixed
> number binary, two different fixed point numbers can be efficiently added or
> subtracted with only a single additional shift operation when compared to
> integer arithmetic.
> Multiplication and division of large fixed point
> numbers will be a little more complex so not to lose any precision, while
> smaller fixed point numbers can be multipled and divided also with only a
> single additional shift operation when compared to integers.
This is certainly an interesting efficiency, but couldn't we just implement
opreator+, etc with Bill's current class? And anyway, is it really that
much faster than plain integer arithmetic? Just seems like we are optimizing
before we are clear on the interface...
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