[OT] - does IP exist?

[Adam D. Ruppe]

Again, these debates are taking too much of my time and I'm getting behind
schedule on more important things, so this will by my last word.

On Mon, Aug 18, 2008 at 10:01:57PM +0000, Manfred_Nowak wrote:
> If a copied object is not forced to hold the exactly same relevant 
> information as the original, then how can you prove for differing 
> objects, that one object is indeed a copy of the other?

if( a is b || a == b ) { writefln("A is a copy of B!"); }

I'll leave writing a.opEquals(b) as an exercise to the reader :)

But for something like files, doing a bit by bit compare gives a good
result. The meta data might be different, but for the purposes of calling
it a copy, the main contents are what matters.

> If sufficient similarity is enough for a copy:
> 1) how do one measure similarity?

Depends on the specific object.

> 2) Is it tolerable, that after some iterated copy steps the rsult can 
> no more considered to be a copy of the original?

Like this?

auto a = whatever;
auto b = a;
auto c = b; // here, c == a, so c is still a copy of a.

It might have been created through a roundabout process, but the end result
is the same.

After that, I'd say that once you do any modifications to the new one
(something like b++;), you no longer have a copy. It would be a derivative
work then.

> If age is an allowed attribute for comparing objects: how can one 
> exclude, that none of the objects is the original; i.e. when you 
> compare an uncle with his nephew, but the original was some anchestor 
> of both?

You can't say this for sure, but in practice, you'd assume whomever
says he has the original first gets to be it until someone comes up
with evidence to challenge that claim.

Above, variable a is considered the original until variable whatever goes
ahead and challenges that in court, using a debugging log as evidence to
prove that he was there before variable a.

> 
> -manfred

-- 
Adam D. Ruppe
http://arsdnet.net