From: Dennis Ranke <dennis.ranke@...>
Date: 2004-02-26T18:59:54+09:00
Subject: Re: Operators +, += and = in Ruby 2

On Wed, 25 Feb 2004 16:12:16 +0100, Robert Klemme <bob.news@gmx.net> wrote:

> Now, wouldn't it be better to turn that around and have people define
> operator += and automatically convert operator + like in:
>
> "x + y" becomes implicitely "x.dup += y"
>
> [...]
>
> What do others think?  Did I overlook something?

Yes, I think so. With your proposed change it would be impossible to 
express operations where the result has a different type than the first 
operand, like, for example:

Float = Vector * Vector   # (dot product)
or
Vector = Matrix * Vector

So in some cases it is not possible to correctly define a *= operator, 
while a * operator is still desirable.

Of course, it would be possible to automatically define a missing +=  
using a defined +, and a missing + using a defined +=. Whether this would 
be a good idea is certainly debatable.

-- 
exoticorn/farbrausch