From: Joel VanderWerf <joelvanderwerf@...>
Date: 2010-06-06T07:55:20+09:00
Subject: Re: 1.9 warning for 'private' and possible bug

> On 2010-06-05 15:25:59 -0700, Joel VanderWerf said:
> 
>> Consider this error:
>>
>> $ cat t.rb
>> module M
>>    private
>>    def attr_accessor(*args); super; end
>> end
>>
>> class C
>>    extend M
>>    attr_accessor :x
>> end
>>
>> C.new.x = 1
>>
>> $ ruby19 t.rb
>> t.rb:11:in `<main>': private method `x=' called for
>> #<C:0x0000000091c670> (NoMethodError)
>>
>>
>> That looks very suspect, so I was about to file a bug report. But then I
>> noticed that there is a warning reported with the -v switch:
>>
>> $ ruby19 -v t.rb
>> ruby 1.9.2dev (2010-05-31) [x86_64-linux]
>> t.rb:3: warning: private attribute?
>> t.rb:11:in `<main>': private method `x=' called for
>> #<C:0x000000012e5670> (NoMethodError)
>>
>>
>> Does anyone understand this warning? Is 'private' (without an argument)
>> deprecated?
> 
> 

Rein Henrichs wrote:
 > This behavior seems consistent with, for instance:
 >
 > class PrivateAccessor
 >  private
 >  attr_accessor :foo
 > end
 >
 > PrivateAccessor.new.foo
 > # => NoMethodError: private method `foo' called for
 > #<PrivateAccessor:0x1017bbce8>


No. The original code is controlling access to the method 
Module#attr_accessor. Your code is controlling access to 
PrivateAccessor#foo.