class Hash

  # Returns a new hash less the given keys.

  def except(*less_keys)
    slice(*keys - less_keys)
  end

  unless defined?(::ActiveSupport)

    # Replaces hash with new hash less the given keys.
    # This returns the hash of keys removed.
    #
    #   h = {:a=>1, :b=>2, :c=>3}
    #   h.except!(:a)  #=> {:a=>1}
    #   h              #=> {:b=>2,:c=>3}
    #
    def except!(*less_keys)
      removed = slice(*less_keys)
      replace(except(*less_keys))
      removed
    end

  end

end