From: Paul Brannan <paul@...>
Date: 2002-02-20T00:23:51+09:00
Subject: Re: Operator overloading and multiple arguments

On Tue, Feb 19, 2002 at 05:37:44AM +0900, Phil Tomson wrote:
> I'm trying to overload the '<=' operator in a class in order to use it for 
> assignment:
> 
> class Blah
>   def initialize(value=0)
>     @value = value
>   end
> 
>   def <=(new_val,time=0)
>     puts "time is: #{time}"
>     @value = new_val
>   end
> end
> 
> a = Blah.new
> a<=5      #prints: time is 0
> a<=(8,10) #results in parse error, doesn't like the ','
> 
> So apparently you can't have more than one argument for an overloaded 
> operator (it actually kind of makes sense) - is there any way to do this?

Oddly enough,

  a.<= 5
  a.<= 8,10

works, but gives me a creepy feeling in my stomach.  Using overloaded
operators for alternative assignment behavior doesn't seem justifiable.
Consider the case where I want to store a Blah object in a binary tree,
and I expect the <= operator to be available for comparing two Blah
objects; what will happen then?

Paul