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Subject: Re: [boost] [Fusion] port to c++0x
From: Christopher Schmidt (mr.chr.schmidt_at_[hidden])
Date: 2009-09-23 15:47:50

Larry Evans schrieb:
> Thanks for all the work.
> However, I was wondering why you couldn't eliminate some of the
> extensive BOOST_PP magic in:
> by using the "tagged multiple inheritance"(TMI) method shown
> around here:
> The only other objection might be to limit the number of instantiations
> because the more template instantiations, the slower the compile
> time; however, Doug Gregor suggested he wasn't too worried
> about that at the bottom of:
> -regards,
> Larry

Thank you very much for your feedback.

I did consider that specific method. I decided against using it due to
the enormous amount of template instantiations and the expensive
type_at. The current implementation is 4-unrolled recursive. I am pretty
certain that it is faster - there are about 4 to 8 times less template
Besides, this is the only place in the native variadic template code in
which I use heavy preprocessor repetition. All other container (besides
fusion::cons) have a clean implementation based on fusion::vector.


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