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Subject: Re: [boost] [xpressive] Performance Tuning?
From: Eric Niebler (eric_at_[hidden])
Date: 2009-07-01 15:20:30

Stewart, Robert wrote:
> Dave Jenkins wrote:
>> "Stewart, Robert" wrote:
>>> I was experimenting with Xpressive to see how it would compare
>>> with some custom, string-based numeric input parsing. The
>>> Xpressive code is over 175X slower than the custom code.
>> Each call to parse() is constructing the sregex variables. If you
>> make them static or move them out of the loop, it should help a
>> lot.
> Thanks, but see my reply to Eric's. While that would help with the
> benchmark performance, the nature of the function I'm testing means I
> can't do that otherwise.

Really what you're saying is: "I can't/don't want to use xpressive in
the ways that are *documented* to make it perform well. Why is it slow?"
You already have your answer.

Eric Niebler
BoostPro Computing

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