Issue #8906 has been reported by ko1 (Koichi Sasada).

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Feature #8906: Freeze Symbols
https://bugs.ruby-lang.org/issues/8906

Author: ko1 (Koichi Sasada)
Status: Open
Priority: Normal
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: current: 2.1.0


Now, Integer and Float objects are frozen objects.
How about to freeze Symbol objects, too?
I think Symbol is friend of Integer.

Current behavior:
  p :foo.frozen?                       #=> false
  :foo.instance_variable_set(:@foo, 1)
  p :foo.instance_variable_get(:@foo)  #=> 1


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Background of this proposal:

Now, I'm working on "GC-able Symbols" feature.
Freezing symbols make this feature easier.

for example:
  (1) set an instance variable @iv for symbol s
  (2) collect s
  (3) generate s
  (4) what value of @iv for s returns?



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