Re: [Boost-users] MPL to get rid of cumbersome switch

From: Delfin Rojas (drojas_at_[hidden])
Date: 2006-03-17 18:20:51

> John Christopher wrote:
> 
> Hello,
> Still reading... Chapter 11 is still a few pages away...
> Any way, I rewrote the program and I have something much simpler.
> The vector of types has not changed:
>     typedef boost::mpl::vector<T0, T1, T2, T3> TTypes; but 
> the Functor has a new switch statement that is much easier to 
> maintain. 
> The nnumber of cases in the switch must be the number of 
> elements in the vector of types... Adding new cases is no big 
> deal anyway.
> switch(i)
> {
> case 0:
>     vec.push_back(new boost::mpl::at<TTypes, 
> boost::mpl::int_<0> >::type);
>     break;
> case 1:
>     vec.push_back(new boost::mpl::at<TTypes, 
> boost::mpl::int_<1> >::type);
>     break;
> ....
> 

Given its prepetitive nature you could use boost preprocessor library to
generate this switch...

-delfin