init.cpp

#include <Rcpp.h>
#include <dplyr.h>

using namespace Rcpp ;
using namespace dplyr ;

#define DPLYR_REGISTER(__FUN__) R_RegisterCCallable( "dplyr", #__FUN__, (DL_FUNC)__FUN__ );

SEXP get_cache(){
    static SEXP cache = 0;
    if( !cache ){
        SEXP vec = PROTECT(Rf_allocVector(VECSXP, 2)) ;
        SEXP date_classes = PROTECT(Rf_mkString("Date")) ;
        SET_VECTOR_ELT( vec, 0, date_classes) ;
        CharacterVector time_classes = CharacterVector::create( "POSIXct", "POSIXt" ) ;
        SET_VECTOR_ELT( vec, 1, time_classes) ;
        UNPROTECT(2) ;
        R_PreserveObject(vec) ;
        cache = vec ;
    }
    return cache ;
}

SEXP get_date_classes(){
    return VECTOR_ELT(get_cache(), 0) ;
}
SEXP get_time_classes(){
    return VECTOR_ELT(get_cache(), 1) ;     
}

extern "C" void R_init_dplyr( DllInfo* info ){
    DPLYR_REGISTER(build_index_cpp)
    DPLYR_REGISTER(registerHybridHandler)
    
    DPLYR_REGISTER(get_time_classes)
    DPLYR_REGISTER(get_date_classes)
}