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Bug #10276

nil/true/false に singleton メソッドを定義できてしまう

Added by znz (Kazuhiro NISHIYAMA) about 5 years ago. Updated about 3 years ago.

Status:
Rejected
Priority:
Normal
Assignee:
-
Target version:
-
ruby -v:
ruby 2.2.0dev (2014-09-21 trunk 47672) [x86_64-linux]
[ruby-dev:48569]

Description

nil/true/false が frozen object なのに singleton メソッドを定義できてしまいます。

% cat /tmp/f.rb
def d(o)
  p o.frozen?
  def o.m; end
rescue
  p [o, $!]
end
d(:sym)
d(1)
d(nil)
d(true)
d(false)
d(Object.new.freeze)
% ruby -v /tmp/f.rb
ruby 2.2.0dev (2014-09-21 trunk 47672) [x86_64-linux]
true
[:sym, #<TypeError: can't define singleton>]
true
[1, #<TypeError: can't define singleton>]
true
true
true
true
[#<Object:0x00000002706730>, #<RuntimeError: can't modify frozen object>]

History

Updated by znz (Kazuhiro NISHIYAMA) about 5 years ago

frozen なオブジェクトに特異クラスが作成できるかどうかも統一されていないようですが、そういうものなのでしょうか?

>> RUBY_DESCRIPTION
=> "ruby 2.2.0dev (2014-09-25 trunk 47711) [x86_64-linux]"
>> class << :sym; end
TypeError: can't define singleton
        from (irb):2
        from /home/kazu/.rbenv/versions/git/bin/irb:11:in `<main>'
>> class << 1; end
TypeError: can't define singleton
        from (irb):3
        from /home/kazu/.rbenv/versions/git/bin/irb:11:in `<main>'
>> class << nil; end
=> nil
>> class << Object.new.freeze; end
=> nil
>>

Updated by akr (Akira Tanaka) about 5 years ago

  • Status changed from Open to Feedback

開発者会議のときに、奇妙だがそういうものとしようということになった覚えがあります。

Updated by akr (Akira Tanaka) about 3 years ago

  • Status changed from Feedback to Rejected

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