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[Rcpp-devel] Exporting C++ enums to R

2 messages · Sameer D'Costa, Romain Francois

Original
Sameer D'Costa
# 
Hi,

I have an enum defined in a C++ library that I would like to export to R. I
saw some references to enums in pkg/Rcpp/inst/include/Rcpp/module/Module.h
but I could not find any examples of enums being used. Through trial and
error I figured out that I could create a dummy class and add the enum to
that (see code below). Can I export the enum directly? I saw references
to RCPP_EXPOSED_ENUM but I could not figure out how to use that macro. Any
help or pointers to examples where enums are used would be appreciated.

Regards,
Sameer

#include "Rcpp.h"

using namespace Rcpp;

class Dummy {
  int x;
  int get_x() {return x;}
};

enum MyEnum {ENUM0, ENUM1, ENUM2};


RCPP_MODULE(EnumMod) {
    class_<Dummy>("EnumMod")
    .default_constructor()
    ;

    enum_<MyEnum, Dummy>("EnumType")
        .value("Enum0", ENUM0)
        .value("Enum1", ENUM1)
        .value("Enum2", ENUM2)
        ;
}
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4 days later
Romain Francois
# 
Le 05/08/13 22:40, Sameer D'Costa a ?crit :
Unfortunately, I think you found the workaround. We need to work on a 
way to expose enums that are outside of a class definition.

Romain