[Rcpp-devel] public data members in modules

[romain at r-enthusiasts.com]

Hello, 

I've added "field" and "field_readonly" to allow exposing public data members of
a c++ class. For example (from the unit tests):

test.Module.member <- function(){

	inc  <- '
	class Num{
	public:
	    Num() : x(0.0), y(0){} ;
	    	    
	    double x ;
	    int y ;
	};
	
	RCPP_MODULE(yada){
		using namespace Rcpp ;
	
		class_<Num>( "Num" )
		
			// read and write data member
			.field( "x", &Num::x )
			
			// read only data member
			.field_readonly( "y", &Num::y )
		;
	}
	'
	fx <- cxxfunction( signature(), "" , include = inc, plugin = "Rcpp" )
	
	mod <- Module( "yada", getDynLib(fx) )
	Num <- mod$Num
    w <- new( Num )
    checkEquals( w$x, 0.0 )  
    checkEquals( w$y, 0L )  
    
    w$x <- 2.0
    checkEquals( w$x, 2.0 )  
    
    checkException( { w$y <- 3 } )
}

I've added a subsection on the vignette to reflect the addition.

Romain