Re: [Boost-users] [Proto] Reducing domain check in operator

Subject: Re: [Boost-users] [Proto] Reducing domain check in operator
From: Eric Niebler (eric_at_[hidden])
Date: 2009-02-26 14:58:23

Joel Falcou wrote:
> Eric Niebler a écrit :
>> Cool.
> 
> Small variation. If I want the domain of A(B) always be X, I just 
> specify it with make_expr ?

Yes, or else make A a Proto terminal in the X domain.

>>> Concerning the other approach, I guess it boils down to have terminal 
>>> of the given function object laying around?
>>>
>>> terminal< exponent_ > exponent  ={{}};
>> ----------------------^ ::type here
>>
>> Right, although it would change the resulting tree, because 
>> exponent(x) would have tag type proto::tag::function instead of 
>> nt2::tag::exponent_.  You'd have to make corresponding changes to your 
>> grammar.
> 
> To be abel to be called and produce reuslts, exponent_ just need to be a 
> Polymorphic Function Object I assume ?

Yes.

>> Hard to say. The only advice I can give is to try it and see.
> 
> Seems I found my occupation for this week-end then.
> My main concern is that having lots of declared but unused const object 
> may force the compiler to compile all fo them aka ending in
> a verrrrrrry long compile-time and prolly large executable too.

You might be right. I'll be interested in your results.

-- 
Eric Niebler
BoostPro Computing
http://www.boostpro.com