Re: [boost] If boost::fusion is the hammer, then what's the nail?

From: Joel de Guzman (joel_at_[hidden])
Date: 2006-12-15 17:14:48

Gennadiy Rozental wrote:
> "David Abrahams" <dave_at_[hidden]> wrote in message 
> news:87irgdxafy.fsf_at_pereiro.luannocracy.com...
>> "Gennadiy Rozental" <gennadiy.rozental_at_[hidden]> writes:
>>
>>> "David Abrahams" <dave_at_[hidden]> wrote in message
>>> news:87psal1e9x.fsf_at_pereiro.luannocracy.com...
>>>> "Gennadiy Rozental" <gennadiy.rozental_at_[hidden]> writes:
>>> Just that after many years of optimizing
>>> performance critical code I gave up doing any "estimations". I was proven
>>> wrong too many times, so that  even test program is not real prove. There
>>> are way too many factors that affect performance of real-life 
>>> applications.
>>> Sometimes the same code compiled with different compilers of in different
>>> hardware will exhibit completely different performance pattern. We could
>>> talk about trends. And in this case I believe trends could be different
>>> depending on circumstances.
>> That's true in most cases, but there's no need to muddy this case with
>> uncertainties.  If you think about it for just a few moments, you'll
>> see there's absolutely no way the tuple version could be worse, and
>> that it would take an optimizer of unheralded brilliance to make the
>> variant version as good.
> 
> Let's just say that we'll have agree to disagree ;)

Please see my other post. You must have missed this reply to your
post when fusion was being reviewed. I've done lots of tests
for variant. It's not as optimal as you think, alas :( Mind you,
I hoped variant would be as fast as it can too because I rely
on it in spirit2.

Regards,
-- 
Joel de Guzman
http://www.boost-consulting.com
http://spirit.sf.net