# File lib/active_model/validations/format.rb, line 14 def check_validity! unless options.include?(:with) ^ options.include?(:without) # ^ == xor, or "exclusive or" raise ArgumentError, "Either :with or :without must be supplied (but not both)" end if options[:with] && !options[:with].is_a?(Regexp) raise ArgumentError, "A regular expression must be supplied as the :with option of the configuration hash" end if options[:without] && !options[:without].is_a?(Regexp) raise ArgumentError, "A regular expression must be supplied as the :without option of the configuration hash" end end