From: nobu.nokada@...
Date: 2003-06-27T20:26:42+09:00
Subject: Re: Using & for arrays of objects

Hi,

At Fri, 27 Jun 2003 09:48:56 +0900,
Krishna Dole wrote:
> I'm having trouble using the & (intersection) method on two arrays of
> objects. I know that if the objects don't have comparison methods, & won't
> work because it is looking at the object IDs rather than values stored in
> the objects, but I can't seem to get & to use the comparison methods I want.

Array#& uses Hash internally due to performance, so you need to
define #hash and #eql? methods.

-- 
Nobu Nakada