From: matz@... (Yukihiro Matsumoto) Date: 2000-02-16T23:59:46+09:00 Subject: [ruby-talk:01460] Re: The return value of Method.arity In message "[ruby-talk:01440] The return value of Method.arity" on 00/02/16, Dave Thomas writes: |I'm trying to come to grips with Method.arity. My understanding is |that it returns the following | | c language methods: n mandatory arguments +n | | n arguments including some -n | that are optional | | attribute setters 1 | | Ruby methods n arguments -n-1 | | n arguments including an -n | array or block | |Is this correct? Oops, it is a bug. That should not be clear difference between C methods and Ruby methods. It should be methods: n mandatory arguments +n n mandatory arguments + optional -n-1 But C methods have no information about number of mandatory arguments, so that arity for all C methods with any optinal arguments return -1. matz.