instance method Module#ruby2_keywords

For the given method names, marks the method as passing keywords through a normal argument splat. This should only be called on methods that accept an argument splat (`*args`) but not explicit keywords or a keyword splat. It marks the method such that if the method is called with keyword arguments, the final hash argument is marked with a special flag such that if it is the final element of a normal argument splat to another method call, and that method call does not include explicit keywords or a keyword splat, the final element is interpreted as keywords. In other words, keywords will be passed through the method to other methods.

This should only be used for methods that delegate keywords to another method, and only for backwards compatibility with Ruby versions before 2.7.

This method will probably be removed at some point, as it exists only for backwards compatibility. As it does not exist in Ruby versions before 2.7, check that the module responds to this method before calling it. Also, be aware that if this method is removed, the behavior of the method will change so that it does not pass through keywords.

例

module Mod
  def foo(meth, *args, &block)
    send(:"do_#{meth}", *args, &block)
  end
  ruby2_keywords(:foo) if respond_to?(:ruby2_keywords, true)
end