Re: [boost] GGL Review

Subject: Re: [boost] GGL Review
From: Phil Endecott (spam_from_boost_dev_at_[hidden])
Date: 2009-11-16 15:38:05

Hartmut Kaiser wrote:
>> Brandon Kohn wrote:
>> There
>> are many buggy floating point boolean op libraries out there. Why do we
>> need another?
>
> I would like to ask you to refrain from spreading FUD with regards to the
> library under review without any concrete proof.

Hartmut, I'm unhappy that you as review manager made that comment.  You 
ought to be more impartial.  I don't think it's unreasonable to call 
the FP robustness issues "bugs".  I think it's very likely that GGL has 
these issues when used with FP coordinates, and I don't accept your 
"concrete proof" requirement for making that allegation.  The library's 
approach seems to be, "if you're not happy with undefined behaviour, 
use an arbitrary-precision coordinate type".  Please correct me if I'm 
wrong, but I believe the library doesn't provide any way to hide the 
arbitrary-precision type and the type conversions from the user as an 
implementation detail, nor does it have a mechanism to fallback only 
when it detects a problem with the FP calculation, nor have any 
benchmarks been done on the arbitrary-precision case.

Phil.