text: #include <cstdio>
  #include <string>
  
  // Example of namespace
  namespace bw {
      
      const std::string prefix = "(bw::string) ";
      
      class string {
          std::string _s = "";
          string ();
      public:
          string ( const std::string & s ) : _s( prefix + s) {}
          const char * c_str() const { return _s.c_str(); }
          operator std::string & () { return _s; }
          operator const char * () const { return _s.c_str(); }
      };
      
  };  // namespace bw
  
  int main() {
      const std::string s1("This is a string");
      std::puts(s1.c_str());
      
      const bw::string s2(s1);
      std::puts(s2);
      
      return 0;
  }