From: Minero Aoki <aamine@...>
Date: 2001-09-28T14:57:18+09:00
Subject: [ruby-talk:21796] Re: Help: how to (re)define the unary minus?

Hi,

  In mail "[ruby-talk:21795] Help: how to (re)define the unary minus?"
    furufuru@ccsr.u-tokyo.ac.jp (Ryo Furue) wrote:

> Hi there,
> 
> I'm wondering how one should (re)define the unary minus operator for a
> class.  The following fails:

>       def -() # unary???
>          Complex.new(-@re, -@im)

>   ./try.rb:17: undefined method `-@' for #<Complex:0xe7f60>
> (NameError)

This error message is a hint.

  def -@   # do not insert spaces between '-' and '@'
    Complex.new(-@re, -@im)
  end

would work.


Minero Aoki