From: "Daniel Schüle" <uval@...>
Date: 2005-11-07T00:47:10+09:00
Subject: Re: what does --can't define singleton method--  mean?

> irb(main):005:0> class << c
> irb(main):006:1> def angle
> irb(main):007:2> (arg/Math::PI)*180
> irb(main):008:2> end
> irb(main):009:1> end
> TypeError: can't define singleton method "angle" for Complex
>         from (irb):6
>         from :0
> irb(main):010:0> c.arg
> => 0.785398163397448
> irb(main):011:0> c.angle
> => 45.0

I think the error message is misleading, because

class << c
	def angle;end
end

should add a singleton method to instance c
or overwrite the behavior of inherited method

as expected the behaviuor of c.angle is changed

it should not "define singleton method for Complex"

Regards, Daniel