From: David Naseby <david.naseby@...>
Date: 2003-11-06T14:46:29+09:00
Subject: Re: Managing metadata about attribute types

>
>Hmm .. by the way, aren't you arguing against duck-typing here?
>If someone deliberately creates a type which is *like* a Float, then
>this code would force it to be a real float (assuming that to_f returns
>a real Float object).

Just weighing in with a small point, but
1.0.to_f #=>1.0

A type *like* a float responds to to_f, to give a float. For any type to act
like a float, it must quack like a float, in the sense it gives a meaningful
float when it hears to_f. #to_x messages are just messages. It is not
casting - unless you are wacky enough to write a #to_f! method. Its asking
the object to show its face as a float. 

David.