Rcpp::NumericVector -> std::vector

vector.r

library(inline)
body='NumericVector xx(x); 
            std::vector<double> X(xx.begin(),xx.end());
            for (int i = 0;i<X.size();i++) {
                std::cout << "X[i] = " << X.at(i) << std::endl;
            } 
            return (xx);'
            
tfun = cxxfunction(signature(x="numeric"),body,plugin="Rcpp")
tfun(c(1,2.2,4,3.19)