RE: [boost] PP interest in facilities for variable length argument lists

From: Josh Dybnis (jdybnis_at_[hidden])
Date: 2003-06-26 13:44:58

Can you elaborate some more on this. Do you mean that when a library
macro calls some user-defined macro, which in turn calls the same
library macro, then it will fail to evaluate? 

I have to admit that I don't grok the magic BOOST_PP uses to make
recursion work. Could the same technique be used here without
duplicating a lot of code from the library?

Thanks,
-Josh Dybnis

--- Paul Mensonides <pmenso57_at_[hidden]> wrote:
> > The nice thing about the implementation is that it is layered 
> > on-top of the existing BOOST_PP _ macros like BOOST_PP_WHILE. 
> > So it doesn't require modifications to the existing library, 
> > and none of the definitions are more that a few lines long. 
> > All the functions live in the namespace BOOST_PP_VA_.
> 
> A bit more on this part, the problem with implementing an algorithm
> on
> top of another algorithm like you do in your code, is that it makes
> the
> algorithm incapable of recursing in contexts where the algorithm
> calls
> some user-defined macro, such as a predicate or operation.
> 
> Regards,
> Paul Mensonides
> 
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