Re: [boost] [xint] Third release is ready, requesting preliminary review

Subject: Re: [boost] [xint] Third release is ready, requesting preliminary review
From: vicente.botet (vicente.botet_at_[hidden])
Date: 2010-05-03 13:41:24

----- Original Message ----- 
From: "DE" <satan66613_at_[hidden]>
To: "Stewart, Robert" <boost_at_[hidden]>
Sent: Monday, May 03, 2010 7:16 PM
Subject: Re: [boost] [xint] Third release is ready,requesting preliminary review

> 
> on 03.05.2010 at 20:39
> Stewart, Robert wrote :
> 
>> DE wrote:
>>>  Stewart, Robert wrote :
>>> > DE wrote:
>>> >> i believe that mutating operations are so expensive that the cow
>>> >> overhead becomes negligible
>>> >> and one can live with it unless he is very pedantic
>>>
>>> > Once again, allow me to point out that the copy was being made in
>>> > order to mutate the copy.  The COW operations are
>>> > superfluous in that case.
>>>
>>> i understand this point
>>> but i see no conflict between those two statements
> 
>> There is no conflict other than that your response was directed to
>> my statement that the COW overhead was superfluous in the context I
>> addressed.  Thus, using COW to satisfy the stated example pessimized the code.
> 
> it does indeed
> but the pessimization is negligible compared to the cost of an
> operation itself
> 
> 
> i suddenly have remebered a rule on optimization: measure, then optimize
> in other words: find a bottleneck and only then optimize the
> code causing it
> in this thread things look the other way around
> you guys make a guess and ask to change/optimize the code using that
> guess as the basis
> sorry, i consider it wrong
> in fact it must be like this:
> - i use it in a <usecase>, i profiled it and found a bottleneck in the
> following piece of code...
> 
> otherwise there is a big chance we are wasting each others time making
> guesses and arguing about implementation details
> because optimizations born from that may be worthless

Do you mean that Chad should remove its COW optimization and mesure and optimize the bottleneck?

Vicente