Vladimir Batov wrote:
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().
Sorry for the late response. I disagree that NULL is invalid. Reading or comparing against the value of a NULL pointer is valid but not so against an uninitialized pointer. There are functions other than strlen where NULL does not bomb but has a well defined meaning and purpose, like strtok. FWIW uninitialized seems to be considered singular by the standard 24.1/5 [Example: After the declaration of an uninitialized pointer x (as with int* x;), x must always be assumed to have a singular value of a pointer. ] -- Michael Marcin