[Rcpp-devel] passing function

cpp <- '
	int n = as<int>(N);
	NumericVector numvec(xvec) ;
	Function f(fun) ;
	for( int i=0; i<n; i++){
		numvec = f( numvec ) ;
	}
	return numvec ;
'

# create a C++ function
funx <- cfunction(signature(N = "integer" , xvec = "numeric", fun = "function" ),
                 cpp, , Rcpp = TRUE, include = "using namespace Rcpp; ")

Now for your questions:

   I see that f is a Function object but what is fun? 

There is no 'fun' but 'funx' is an R function created by cfunction() [ of the
inline package ] containing executable code created by cfunction() from the
source code submitted via variable 'cpp'.