c++ - What is the benefit of having a String class for Rcpp -

i wondering benefit having rcpp string class (documented here).

it possible convert between rcpp:string , std::string, why not use std::string since many of methods implemented. i'm guessing there must reason doing this. advice.

easy: there strsxp , rcpp types first , foremost proxy objects underlying r types. no copies.

using std::string entail copies on way in , out. don't want that.