When I write code that does this:

  class Foo
    def self.[](name, *args)
      p name, args
    end

    X = self
    _ = 1

    foo =
     [       :x, :y, :z, :a, :b ]
    X[ :foo,  _,  _,  _,  _,  _ ]
    X[ :foo,  _,  _,  _,  _,  _ ]

  end

Then I get output like this:

  [pbrannan@zaphod tmp]$ !ritten
  ruby -w bracket.rb
  bracket.rb:11: warning: useless use of [] in void context
  :foo
  [1, 1, 1, 1, 1]
  :foo
  [1, 1, 1, 1, 1]

However, if I take out the second X[ :foo, ... ] line, then I do not get
the warning.

I'm doing this because it is convenient to specify a table of data this
way.

1) Why do I get this warning?
2) Is this a bug?
3) Is there a workaround until this can be fixed (or if it will be fixed)?

Paul