Re: [boost] [serialization]Serialisation/deserialisationoffloating-point values

From: Paul Giaccone (paulg_at_[hidden])
Date: 2006-05-02 12:46:08

Sebastian Redl wrote:

>Paul A Bristow wrote:
>
>  
>
>>The Standard is imprecise on this issue, but I feel it is a very poor do
>>that such a bizarre small range of values should be wrong.
>>
>>Feels like an off-by-one rounding bug to me.
>> 
>>    
>>
>I tend to agree with the MS engineers here. I've found out only 
>yesterday that the FPU/math library is not entirely deterministic in 
>some calculations (including square roots and trigonometry, typical 3d 
>stuff), so I think worrying about serialization/deserialization is useless.
>  
>

But we're not talking about calculations here - you always get rounding 
error in floating-point calculations, and we handle it accordingly. But 
if I write out 1.2345 and it becomes 1.2346 when I read it back, that's 
cause for concern.

Paul