On Nov 10, 9:43 pm, Vasyl Smirnov <vasyl.smir... / gmail.com> wrote:
> I've tried to freeze a Set instance, and it turned out not working:

The following fixes the problem:

require 'set'
# Patch for Set to make freeze work.
class Set
  def freeze
    @hash.freeze
    self
  end
  def frozen?
    @hash.frozen?
  end
end