Ruby does the trick because an assignment on a object member is done by calling the method member= on the object.

attr_accessor is just a function which generates the most simple case on which a member variable of the same name is assigned.

Even if you can define

def member=(a,b) # do something end

there is no way to call this using the assignment syntax.

You could of course do obj.send and send the method name and parameters to reach that method.

What you can actually do, is define the setter to accept an array of arguments:

require 'pp'

class Foo def bah=(*opts) pp *opts end end

f = Foo.new f.bah = 1 f.bah = 1, { :param => 1}

In the first case, you will get an integer, in the second case, an array where the first element is the integer, and the second element is a hash with the options.

My experience with methods taking bool flags to modify behavior is not good