Re: [boost] lexical_cast optimization

Subject: Re: [boost] lexical_cast optimization
From: remi.chateauneu_at_[hidden]
Date: 2008-12-04 16:57:24

This implementation of itoa is rather fast and open-source, based on a 
lookup up table of groups of four digits:
https://sourceforge.net/projects/itoa

"Fast implementation of the old deprecated itoa(), lltoa() etc... plus 
some C++ wrapping. Theoretically controversed but practically very useful."

The source is visible here, with a humble attempt to integrate it into 
Boost :
http://itoa.cvs.sourceforge.net/viewvc/itoa/itoa/

Thorsten Ottosen wrote:
> Darren Garvey skrev:
>> 2008/12/3 David Abrahams <dave_at_[hidden]>
>>
>>> Someone was asking me today about the inefficiency of lexical_cast for
>>> its common itoa/atoi-like usage, and it occurred to me that it could
>>> *easily* be optimized to handle the common cases by dispatching to
>>> itoa/atoi ftoa/atof where available, and even sprintf.  Seems like a
>>> great idea to me.
>>>
>>> Thoughts?
>>>
>>
>> You may find the following interesting:
>>
>> http://lists.boost.org/Archives/boost/2007/11/131001.php
>>
>> I'd quite like to know if Johan got these changes into the library. 
>> Any news
>> on this?
>>
>
> I haven't looked at the implementation, but I know Matthew Wilson had 
> a series of articles in CUJ about fast string to integer conversions. 
> IIRC, he was doing much better than the functions from the C library:
>
> http://www.ddj.com/cpp/184403874
>
> I guess it might be possible to optimize the floating point casts too, 
> albeit it might be somewhat harder.
>
> -Thorsten
> _______________________________________________
> Unsubscribe & other changes: 
> http://lists.boost.org/mailman/listinfo.cgi/boost
>