Re: [Boost-users] Some questions on the interval library

From: Nikolaos Kavvadias (nkavv_at_[hidden])
Date: 2007-06-20 09:36:33

Guillaume Melquiond wrote:
>> The SELECT operation would be:
>>
>>             -> src1, if cond!=0
>> dst <= |
>>            |
>>             -> src2, if cond=0
>>     
>
> Generally, you have to add a third branch when you can't decide whether
> cond == 0 or cond != 0 (in case cond is not degenerate yet it contains
> zero). This third branch will store hull(src1, src2) into dst.
>   

Dear Guillaume

thank you for your answer, you have also covered a couple of questions 
that would eventually come up.
In some cases, the "gating" variable (cond in the expression above) 
would be generated as a result of other computations (and not read as 
input to the entire graph/sequence), so it is not right for me to think 
that it would be described by a degenerate interval in all cases. The 
third branch in your expression is thus necessary.

Kind regards
Nikolaos Kavvadias

PS: Nice documentation and examples, comparable to the ones in the BGL 
that had me going there. Thanks again.