Ah, so this probably tells the compiler where to insert the free? If I gave it a local lifetime it would free the memory on function return for example, even if I tried to return a reference to it? Basically Rust just forces you to code in the memory freeing at the definition state of variable creation?
Not quite. Lifetime annotations prevent you from accidentally using references after the value they refer to has been freed. They track how long things will live, instead of defining how long they will live.
Basically they turn use-after-free errors into compile errors.
(I'm using 'free' here to mean cleaned up in general. Lifetimes can track stack values.)
It looks like I will just have to bite the bullet and actually read the rust book back to front. I find static particularly confusing because of the seemingly contradictory meanings that are all jumbled up in my head. The English meaning of immutable, the Java meaning of instance agnostic, and this Rust meaning of immortal lifetime.
> It looks like I will just have to bite the bullet and actually read the rust book back to front.
I mean, there you have it, right? Not a diss on you specifically, but I've often noticed that some people will complain about something, but then it comes out that they actually haven't learned it deeply enough, they're just going on what they either learned so far, learned that something in a haphazard way, or didn't learn it at all.
I used to do the same, so no shame, starting off writing programs as practice and googling things along the way because everyone on any programming thread says "the best way to learn is by building, not doing tutorials" but that's not necessarily true. Sure, I have learned a lot by building, but I've often spent longer simply running around googling and learning bits and pieces than the time I'd spend actually learning something top to bottom, front to back, from scratch. So I actually like and see the value of tutorials now.
Once I read The Rust Book front to back like you said, I understood a lot more of the language than my previous attempts to learn it a few years ago. Doing Rustlings at the same time was great too.