[Rcpp-devel] Enquire on Rcpp::wrap or equivilant

Dirk Eddelbuettel edd at debian.org
Sun Dec 5 20:33:29 CET 2010

On 5 December 2010 at 20:09, Tama Ma wrote:
| Dear Rcpp developers,
| May I kindly enquire on the wrapping of a portion of a container into an R
| numeric array by Rcpp::wrap?
| For example, I wish to have:
| template <class size_type, class element_type>
| Rcpp::NumericVector 
| convert
| ( element_type* obj
| , size_type* n
| )
| {
| Rcpp::NumericVector Rvec;
| Rvec.reserve(n);
| std::copy( *obj , *(obj+n),  std::back_inserter(Rvec));
| return Rvec;
| }
| May I know how I can do this?

I don't follow. Rcpp::NumericVector is _not_ templated. It always uses
double; and Rcpp::IntegerVector uses int and so on.

So your 'convert' should not be a template function.  

Next, because you stay NumericVector (or equivalent) there is no need to
reinvent wrap() as it already works.

But maybe I misunderstood.  Also:

On 5 December 2010 at 19:57, Tama Ma wrote:
| 	I agree with you that for fast development, inline looks more attractive. 
| 	Thank you for sharing!

You may want to glance at the list archives. There have been quite a few working
examples and gems posted.

Cheers, Dirk

Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com

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