[boost] [tokenizer] about class escaped_list_separator

I have a question about class escaped_list_separator. when I read member function do_escape,I found that only three escape sequences are supported, they are \\, \", \n. otherwise, an exception will be thrown. but in fact, a character can be represented in a numeric form, for example, we can use '\137' or '\x05f' to represent '_', I think this is not an exceptional case. why escaped_list_separator not to process this kind of case? Can anyone please give some help or tips? thanks Liang --------------------------------- Do You Yahoo!? 捇誥轎煤G蚘眊ㄜ笢弊菴珨橈拸嶼僵蚘璃玊閉湮蚘眊