[Rcpp-devel] Rcpp modules and parsing an object back and forth between R & C++

[Hadley Wickham]

>> Until that happens, is it possible to write my own as and wrap methods?
>>
>
> Sure.
>
> For as, You can get a Simple* using this:
>
> Simple* obj = as_module_object<Simple>(x) ;
>
> For the details, see as.h, this will call this:
>
>         template <typename T> object<T> as_module_object(SEXP x){
>             return (T*) as_module_object_internal(x) ;
>         }
>
>  and then this:
>
>         namespace internal{
>             void* as_module_object_internal(SEXP obj){
>                 Environment env(obj) ;
>                 SEXP xp = env.get(".pointer") ;
>                 return R_ExternalPtrAddr(xp );
>             }
>         }
>
> which uses the way we structured the c++ class around the reference class.
>
> but writing RCPP_EXPOSED_AS(Simple) is enough I think so that you get
> "as<Simple>" directly.

Awesome - thanks!  That works perfectly.

Hadley

-- 
Chief Scientist, RStudio
http://had.co.nz/