Re: [boost] Fixed-Point Decimal Type

From: Howard Hinnant (hinnant_at_[hidden])
Date: 2001-05-15 15:14:03

On Tuesday, May 15, 2001, at 03:33  PM, Gabriel Dos Reis wrote:
> Beman Dawes <bdawes_at_[hidden]> writes:
>
> | So a question is do you support that by having a whole bunch of 
> different
> | functions, or by the class template taking some kind of a parameter
> | (perhaps a traits or policy class) performing the rounding desired?
>
> I'm leaning toward a trait-based solution.

I'm not positive that a trait-based solution is not the way to go, but 
I'm not yet convinced it is yet either.  One of the uses for rounding 
mode manipulation is to run a computation with it set two ways to get a 
feel for the roundoff error in the result.  By making rounding mode a 
compile time decision one is mandating that such users will have twice 
the code size (than if it is a run time parameter).

In general I'm a very big fan of moving as much computation as possible 
to compile time.  But part of me is questioning a compile time rounding 
mode.  C describes rounding mode in the context of a floating point 
environment (which can be manipulated at run time).  That model may be 
worthy of study.

-Howard