On 06/11/2010 08:15 PM, Robert Dober wrote:
> On Fri, Jun 11, 2010 at 6:47 PM, Robert Klemme
> <shortcutter / googlemail.com> wrote:
>> On 10.06.2010 18:27, Robert Dober wrote:
>>> On Thu, Jun 10, 2010 at 6:10 PM, Robert Klemme
>>> <shortcutter / googlemail.com> wrote:
>>>
>>>> http://blog.rubybestpractices.com/posts/rklemme/018-Complete_Class.html
>>>>
>>>> http://blog.rubybestpractices.com/posts/rklemme/019-Complete_Numeric_Class.html
>>> I
>>> You define #eql? and #hash for your convenience. So good, so bad. My
>>> question simply was: Show my why *not* redefining #hash and #eql? will
>>> cause problems, because that was Wilson's statement. I am still
>>> waiting :(.
>> The advice to implement #eql? and #hash really only makes sense if
>> equivalence can reasonably be defined for a class and if instances of that
>> class should be used as Hash keys or in Set.  If not at least equivalence
>> can be defined other than via identity (which is the default) then it is
>> perfectly reasonable to not override both methods and go with the default
>> implementation.
> But that was *exactly* my point.

I don't think we disagree, nor do I argue with you.  I just posted blog 
links as illustration to Rein's point about how to implement those methods.

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/