reserse a string in cpp

reverse_string.cpp

#include <iostream>
#include <string>

std::string reverse(std::string str){
    if(str.empty()){
        return "";
    }
    int last_elem_index=str.size()-1;
    return str[last_elem_index] + reverse(str.substr(0, last_elem_index));
}

int main(){
  std::string str="hasan";
  std::cout<<"Reversed string of '"<<str<<"' is '"<<reverse(str)<<"'"<<std::endl;
  return 0;
}