code: func copyRouteConf(r routeConf) routeConf {
  	c := r
  
  	if r.regexp.path != nil {
  		c.regexp.path = copyRouteRegexp(r.regexp.path)
  	}
  
  	if r.regexp.host != nil {
  		c.regexp.host = copyRouteRegexp(r.regexp.host)
  	}
  
  	c.regexp.queries = make([]*routeRegexp, 0, len(r.regexp.queries))
  	for _, q := range r.regexp.queries {
  		c.regexp.queries = append(c.regexp.queries, copyRouteRegexp(q))
  	}
  
  	c.matchers = make([]matcher, 0, len(r.matchers))
  	for _, m := range r.matchers {
  		c.matchers = append(c.matchers, m)
  	}
  
  	return c
  }
docs: // returns an effective deep copy of `routeConf`