From: Moore, Paul (paul.moore_at_[hidden])
Date: 2002-03-12 04:13:27
From: Beman Dawes <bdawes_at_[hidden]>
> Let me try to answer this to make sure I understand Paul's
> position (so I can repeat it to the LWG).
>
> Yes, rational is parameterized on the integer type, and so
> can be used with any build-in integer or user-supplied class
> which meets the requirements.
>
> However, because of subtle rounding, precision, and other issues
> not well-known to most programmers, not all integer types are
> really suitable for most applications. In fact, the most
> suitable integer type would often be a unlimited-precision integer,
> yet neither Boost nor the standard currently have such a type.
>
> Thus even though rational is itself ready for standardization,
> some people might feel it would be more appropriate to wait
> until there is also an unlimited-precision integer class available
> for standardization.
>
> Paul, please correct me if I've got this wrong:-)
That's exactly right. The only point I'd add (as background) is that I don't
feel that there is any significant real-world experience to indicate how
likely the issues with using limited-precision integers would be to cause
problems in practice. This makes assessing the risks difficult.
Thanks for taking the time to get this all clear,
Paul.