[Rcpp-devel] Fwd: Re: Making objects in the C++ "side" persistent

[Dirk Eddelbuettel]

On 18 June 2014 at 15:47, Martyn Plummer wrote:
| On Wed, 2014-06-18 at 09:09 +0900, Martin Jakt wrote:
| > On Tuesday 17 Jun 2014 19:34:59 Krzysztof Sakrejda wrote:
| > > On Tue, Jun 17, 2014 at 7:30 PM, Martin Jakt <mjakt at z2.keio.jp> wrote:
| > > >> if (identical(data_ptr, new('externalptr'))) return("No data available
| > > >> to retrieve.")
| > > > 
| > > > thanks. I think it would have taken me a long time to come up with that
| > > > from the documentation. It seems curious there's no direct way.
| > > 
| > > Yes... so it comes with the caveat that I'm not sure if this is
| > > documented behavior
| > > and the R developers might decide to change it (?)  If this is somehow
| > > documented or if there is an Rcpp implementation which gets closer to
| > > documented behavior I would love to know.
| > 
| > that's a good point. Perhaps a question for the r-dev mailing group. I've not 
| > registered for it, but seems like it might be a good idea.
| 
| There is no R-level API for external pointers. You are expected to
| questions like "is it null?" on the C side.

Thanks for clarifying.  This was my gut reactiont too, but as I hadn't needed
this yet in project I hadn't really worried about it too much.

Dirk

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