Re: [boost] [mpl] +[fusion] + [phoenix] undocumented hard-coded limit=50

Subject: Re: [boost] [mpl] +[fusion] + [phoenix] undocumented hard-coded limit=50
From: Mathias Gaunard (mathias.gaunard_at_[hidden])
Date: 2012-03-19 15:58:18

On 19/03/12 18:24, Hite, Christopher wrote:
> This is a re-post of " [boost] BOOST_PP_ITERATE for huge mpl and fusion".  I think problem may be that I didn't target a particular library because it happens in three.
>
> There is an undocumented hard-coded limit of 50 in MPL, Fusion, and Phoenix.
>
> I count two impls
> 1) has 20 elements all generated
> boost_1_49_0/boost/mpl/aux_/preprocessed/gcc/vector.hpp
>
> 2) stops at 50
> boost_1_49_0/boost/mpl/vector/vector50.hpp
>
> I don't know if there's a way to generate more.  Probably you need python.  If that's the case, IMHO this should be documented so users can do it.
>
> This doesn't  work:
> #define BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS
> #define BOOST_MPL_LIMIT_VECTOR_SIZE 60
> #include<boost/mpl/vector.hpp>
>
> boost_1_49_0/boost/mpl/vector.hpp:36:73: fatal error: boost/mpl/vector/vector60.hpp: No such file or directory
>
> Can someone please help.  I've upgraded my copy of boost.  I've tried figuring out how these headers work.  I'm pretty sure I could fix it if I really had to by replacing the 50 in the last file with the *_SIZE.
>
> I have this ugly hack in my code to keep things working.  Would someone please help?!?  Acknowledging the problem would be a start.

Did you try filing a bug?

I would have thought that this is a bug, but it could be intentionally 
limited to 50.