code: func doDemangle(out *bufio.Writer, name string) {
  	skip := 0
  	if name[0] == '.' || name[0] == '$' {
  		skip++
  	}
  	if *stripUnderscore && name[skip] == '_' {
  		skip++
  	}
  	result := demangle.Filter(name[skip:], options()...)
  	if result == name[skip:] {
  		out.WriteString(name)
  	} else {
  		if name[0] == '.' {
  			out.WriteByte('.')
  		}
  		out.WriteString(result)
  	}
  }
docs: // Demangle a string just as the GNU c++filt program does.