Learn Rust the Dangerous Way - the unsafe-first tutorial

[cbiffle]

@Ixrec

Aside from the #[allow(...)] thing that others mentioned already, the only potential improvement that jumped out to me is this: I'm of the opinion that we should avoid saying things "this unsafe code is safe, but that unsafe code is unsafe"

Yeah, I agree, actually. I went back and forth on phrasing there. To some degree, I like the juxtaposition of things like "making safe out of unsafe," but I also see that it could be confusing.

I'm a fan of the sound/unsound distinction that @CAD97 raised, and I don't think it's excessively jargony. I'll play with the wording.

@bogmihdav

However, it may be a good idea to change the order of lessons around a bit. The way it looks right now, I'd expect the typical C programmer to look at the first few diffs, then conclude "Rust is way too verbose/complicated, I already know C and can handle memory just fine, because I'm a Good Programmer™", which means that most of them are never going to get to the good parts.

I think that's a real risk, but I'm also not sure that I can reach someone who's approaching the tutorial looking for reasons to stop reading it. I could be more forceful in Part 1 pointing out that the code is going to get worse before it gets better, I suppose.

@ZiCog

At the end of the day checks are done by the compiler, or they are not done. "checked"/"unchecked".

I agree that the words are uncomfortably similar. Unchecked/checked isn't the distinction we're trying to make, though -- it's between these cases:

1. This bit of code is written using safe parts (in the Rust sense) and is sound. (Which should be true of all safe code, but sometimes safe code has bugs.)
2. This bit of code is written using unsafe parts and is unsound (which is usually what happens the first time I try to write something using unsafe).
3. This bit of code is written using unsafe parts and is nevertheless sound.

Both 2 and 3 are "unchecked" in the sense that the compiler doesn't have our backs.

I think the safe/sound distinction appeals to me because of the English expression "safe and sound" meaning that something is comfortably secure (and probably also warm and cozy). With Rust, achieving "safe and sound" is relatively easy.

...now I feel like I want a Rust sweater.