This sounds like a great way to lose data when the machine dies unexpectedly.
1,344 karma · joined November 20, 2020
Source: I'm a student there and tried it out of curiosity.
Third and fourth are only defined in some implementations.
The difference is that type theories are much less of a "solved" problem and a lot of the variations are subject to ongoing research. As a consequence we're still at the stage where we're trying to figure out the "deciding how to decide", as opposed to programming languages, where decision criteria are relatively well understood.
It did, "const" exists since C89.