Re: [boost] [uuid] Interface

Subject: Re: [boost] [uuid] Interface
From: Scott McMurray (me22.ca+boost_at_[hidden])
Date: 2008-12-23 18:43:00

On Tue, Dec 23, 2008 at 18:27, Vladimir Batov <batov_at_[hidden]> wrote:
>
> For all practical purposes the above makes p1 and p2 quite
> naughty/bad/invalid compared to the well-behaving p3. Despite NULL's quite
> official status in the language(s), strlen() clearly "thinks" that NULL is
> anything but valid and bombs spectacularly. Then, I habitually extended that
> notion onto any foo::null() and ultimately to uuid::nil().
>

I don't really have any strong objections to your description insofar
as it applies to char* in the context of "C Strings", but I completely
disagree with extending it to uuid.

find_by_uuid(uuids::nil()); and
find_by_uuid(uuids::native_generator()()); will behave identically
(assuming you don't have anything keyed by nil -- which you shouldn't
-- and assuming you don't hit a collision -- which a time- and
mac-address-based UUID effectively prevents).

So how is nil any less valid?  Your belief for char* comes from
preconditions on common functions, so what functions (and thereby
preconditions) are you using to apply the same reasoning to UUID?