std::map<std::string, std::string> props;
std::string value("1");
std::string key("type");
props.insert(std::pair<std::string, std::string>(key, value));

/** There is also a templated copy ctor for the @c pair class itself.  */
  template<class _U1, class _U2>
    pair(const pair<_U1, _U2>& __p)
: first(__p.first), second(__p.second) { }
};