Re: [boost] [uuid] Interface

Subject: Re: [boost] [uuid] Interface
From: Vladimir Batov (batov_at_[hidden])
Date: 2008-12-23 18:27:12

>> the same -- 'm_uuid' initialized invalid -- but explicit about what it 
>> actually does.
>
> I realize invalid vs nil/null was discussed earlier but I still don't like 
> using those terms interchangeably.

I've been wondering where that "invalidity" property of nil/null comes from 
for me? For me it certainly started with K&R stating "The symbolic constant 
NULL is ... to indicate more clearly that this is a special value for a 
pointer." That is, it was not just another but special pointer to start 
with. Then, through many years, that "special" property has been firmly 
ingrained for me as "invalid" due to

char* p1;
char* p2 = NULL;
char* p3 = "mama";

strlen(p1); // bombs
strlen(p2); // bombs
strlen(p3); // good

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().

Anyone with more descriptive suggestions?

Best,
V.