On Dec 25, 2012, at 6:39 AM, andre__ wrote:
> Hi,
>
> I am using swig to build a wrapper for an c-function to use it in R. I would
> like to define a generic function, which gives back a void pointer. On the R
> side, I know what this pointer is pointing to, whether it is an integer or
> an string, or something else... but I need to somehow reinterpret the
> resulting "externalptr" into another form...
>
> a function that looks like the following:
>
> *void* test(){
> std::string str="test";
> return str.c_str();
> }*
>
> when I call this from R:
>
> *str <- test()
> typeof(str) % result is: "externalptr"*
>
> how could I reinterpret this to a charcterarray, to a numeric, to list, or
> ...
>
The simple answer is you can't. External pointers are entirely opaque to R, so
*you* have to write that code that interprets them. Obviously it's then up to
you to create the corresponding R object from the external pointer.
You may want to have a look at interface packages like Rcpp, rJava, Rserve, ...
to understand how objects are converted to/from other languages.
Cheers,
Simon
> Thanks for any suggestions ;)
>
>
>
> --
> View this message in context:
> http://r.789695.n4.nabble.com/reinterpreting-externalptr-in-R-tp4653908.html
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>
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