On Thu, 4 Mar 2021 at 17:39, Subhomoy Ghosh <subhomo...@gmail.com> wrote: > > Hi, > > This is related to my post. My question is in the same spirit except for > one additional complexity. How can one create a new instance of a template > class object with a pointer on it and create an external pointer that can be > further passed as an argument of a function? Here is a small example of my > goal that will obviously not run and show "Use of class template Uniform2 > requires template arguments".
You can create a non-template parent class (e.g., Distribution) from which your template class derives. Then you just return a pointer to the parent. In [1] you'll see an example of this (Activity is the parent class; Seize, Release and the others are template classes that inherit from Activity). In your example, you can use something like Rcpp::XPtr<Distribution> ptr(new Uniform2<double>(as<double>(max), D ), true); [1] https://github.com/r-simmer/simmer/blob/master/src/activity.cpp Iñaki > // template class > template <typename T> > class Uniform2 { > > public: > Uniform2(T max_,mat D_) : > max(max_), D(D_) {} > > ~Uniform2(){}; > > T max; > mat D; > }; > > > /// get function > // [[Rcpp::export]] > XPtr<Uniform2> getUniform(const mat &D, SEXP max,char type) { > // create pointer to a template Uniform object and > // wrap it as an external pointer > if(type=='double') { > Rcpp::XPtr<Uniform2> ptr(new Uniform2<double>(as<double>(max), D ), > true); > return ptr; > } else if(type=='int') { > Rcpp::XPtr<Uniform2> ptr(new Uniform2<int>(as<int>(max), D ), true); > return ptr; > } > // return the external pointer to the R side > return Rcpp::XPtr<Uniform2>(R_NilValue); > } > > > > //do something > // [[Rcpp::export]] > double test2(double z, XPtr<Uniform2> xp) { > > double CC= z * xp->max; > > return CC; > > } > > Thanks, > Subhomoy > _______________________________________________ > Rcpp-devel mailing list > Rcpp-devel@lists.r-forge.r-project.org > https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel -- Iñaki Úcar _______________________________________________ Rcpp-devel mailing list Rcpp-devel@lists.r-forge.r-project.org https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
