# File lib/cairo.rb, line 22
    def __add_one_arg_setter(klass)
      names = klass.instance_methods(false)
      names.each do |name|
        if /^set_(.*)/ =~ name and
            not names.include? "#{$1}=" and
            klass.instance_method(name).arity == 1
          klass.module_eval("def #{$1}=(val); set_#{$1}(val); val; end")
        end
      end
    end