Re: [boost] [test] Buglet in floating point comparison code.

From: John Maddock (john_at_[hidden])
Date: 2006-08-04 05:10:23

Gennaro Prota wrote:
> Shouldn't the comment read 0/x or 0/anything?

Probably.

>> +       // the result really is zero here no matter what the
>> denominator:
>
> Unless the denominator is zero, in which case returning zero is a
> convention.

Not in this case: the code calculates relative error, if the numerator is
zero then the relative error is zero whatever the denominator is (including
zero).

> Could you please clarify the context a bit? Would this, in general, be
> called also when numeric_limits is not specialized? When a
> specialization exists I would return (std::numeric_limits<>::max)();
> when it doesn't, how can one be sure that an FPT can be constructed
> from the integer 1000000? Sorry if this is just noise; I just thought
> better *I* raise some noise now than some executable somewhere will do
> it later :-)

The patch is *only* called when numeric_limits is not specialised, there is
already an "if" case to handle that, this just adds the "else" :-)

John