Re: [Boost-users] large enum and native array indexing

Subject: Re: [Boost-users] large enum and native array indexing
From: Hicham Mouline (hicham_at_[hidden])
Date: 2009-01-15 05:34:38

>I would say that the easiest way is to use the preprocessor. 
>#define BOOST_PP_LOCAL_MACRO(n) template<> struct 
>Position<BOOST_PP_CAT(OP, n)> { static const size_t value = n - 1; }; 
>#define BOOST_PP_LOCAL_LIMITS (1, MAX_OP) 
>#include BOOST_PP_LOCAL_ITERATE() 
>In Christ, 
>Steven Watanabe 

I think I wasn't clear enough:

the 3rd party lib (which I can't change of course) provides, 
enum Op {
  OPone = 7,
  OPtwo = 9,
  OPthree = 45,
  OPfour = 7667  // there is no pattern in the names nor the numbers.
}; // in fact, there are a hundred entries

and I wished to generate from Op

template<> struct Position<OPone> { static const int value = 0; }
template<> struct Position< OPtwo  > { static const int value = 1; }
template<> struct Position< OPthree  > { static const int value = 2; }
template<> struct Position< OPfour  > { static const int value = 2; }

I suppose there is no way to automagically generate the template specs
from the enum?

regards,