Boost logo

Boost Users :

From: Yuval Ronen (ronen_yuval_at_[hidden])
Date: 2005-01-19 02:17:43

>>1. lexical_cast(Source arg) takes the source argument by value. Why not
>>by const& ? Calling lexical_cast(some_basic_string) now makes a copy of
>>the source argument for no reason.
> There numerous optimization/enhancements that could be done to lexical_cast.
> In my version I use different interpretators, type wrappers, specializations
> e.t.c. And still in my recent study I found that lexical_cast ~ 20 times
> slower then sprintf and ~200 times slower then my own handcrafted version
> for decimal integer parcing. Conclusion: do NOT use lexical_cast in
> performance critical (even performance aware) parts of your code. The only
> place where I use it is during initialization. Accordingly no need to bother
> about reverence vs. value semantic.
>>2. lexical_cast ignores trailing whitespaces, but not leading
>>whitespaces. Meaning that
> My recomendation is: trim the value on both sodes before cast. And do not
> rely on lexical cast to detect your whitespaces.

Yep, that's a possibility that will work (and will add another string
copy to the mix)...

Boost-users list run by williamkempf at, kalb at, bjorn.karlsson at, gregod at, wekempf at