From: "shugo (Shugo Maeda)" <redmine@...>
Date: 2013-11-30T10:48:32+09:00
Subject: [ruby-core:58706] [Backport 200 - Backport #8872] Case statements	do not honor a refinement of the '===' method


Issue #8872 has been updated by shugo (Shugo Maeda).


Could anyone tell me use cases of this feature?

I think refinements are for object-oriented ways using dynamic dispatch, but case expressions are not for such object-oriented ways.
----------------------------------------
Backport #8872: Case statements do not honor a refinement of the '===' method
https://bugs.ruby-lang.org/issues/8872#change-43272

Author: jconley88 (Jon Conley)
Status: Assigned
Priority: Normal
Assignee: matz (Yukihiro Matsumoto)
Category: 
Target version: 


=begin
Below, I've redefined the ((|===|)) method of symbol to always return true.  In ((|RefineTest#uses_refinement|)), I call ((|===|)) directly and the refined method is called.  In ((|RefineTest#does_not_use_refinement|)), the ((|===|)) method is called indirectly through a case statement.  If the refined ((|===|)) method was called, the result should be ((*'The refinement was used'*)), but this code currently returns ((*'The refinement was not used'*)).

 module RefineSymbol
   refine Symbol do
     def ===(other)
       true
     end
   end
 end
 
 using RefineSymbol
 
 class RefineTest
   def uses_refinement
     :a === :b
   end
 
   def does_not_use_refinement
     case :a
     when :b
       'The refinement was used'
     else
       'The refinement was not used'
     end
   end
 end
 
 rt = RefineTest.new
 rt.uses_refinement   # => true
 rt.does_not_use_refinement  # => expected 'The refinement was used' but got 'The refinement was not used'
=end



-- 
http://bugs.ruby-lang.org/