From: eregontp@...
Date: 2020-09-02T20:46:46+00:00
Subject: [ruby-dev:50954] [Ruby master Bug#9815] attr_reader doesn't warn on a uninitialized instance variable

Issue #9815 has been updated by Eregon (Benoit Daloze).


What was the rationale here to have different behavior?

Which C function is used by `attr_reader` seems an implementation detail.

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Bug #9815: attr_reader doesn't warn on a uninitialized instance variable
https://bugs.ruby-lang.org/issues/9815#change-87379

* Author: ko1 (Koichi Sasada)
* Status: Rejected
* Priority: Normal
* Assignee: matz (Yukihiro Matsumoto)
* ruby -v: confirmed by 1.9.3-2.2.0
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN
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attr_reader で定義したメソッドでは、-w 時に、未設定の警告「warning: instance variable @bar not initialized」みたいなのが出ないんですが、そういうもんでしょうか。

~~~ruby
class C
  attr_reader :foo
  def bar; @bar; end
end
C.new.foo
C.new.bar #=> t.rb:4: warning: instance variable @bar not initialized
~~~

この例では、foo と bar は、同じ意味だと思って居たのでびっくりした次第です。




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