NumericBox unsafe double conversion

[Jan Holesovsky]

Hi Tamás,

Zolnai Tamás píše v St 20. 03. 2013 v 22:33 +0100:


> Yes, I give it a try.

Great, thanks a lot! :-)

> I think the mentioned multiplication is in
> MetricField::ConvertDoubleValue(), which not need to change, as I see.

So whenever we are converting to and from double, there is the risk of
losing precision.  I guess the best would be to change
ConvertDoubleValue() to sal_Int64 too [and change the name
accordingly ;-)], and use BigInt (see tools/inc/tools/bigint.hxx) for
the computations not to overflow.

Though - looking at BigInt - I am afraid you will have to add
BigInt( long long nVal ) constructor in order to make 32bit
architectures happy when you provide them with sal_Int64.

Similarly, you will have to create an operator long long() const; that
would return the long long - and would do that even in the bIsBig case
when the value is larger than long, but still fits sal_Int64.

I am sorry this is getting complicated - but I believe this is a cleanup
that is still worth doing :-)

All the best,
Kendy