Indexing into arrays and vectors is really wise to avoid.
The same day Cloudflare had its unwrap fiasco, I found a bug in my code because of a slice that in certain cases went past the end of a vector. Switched it to use iterators and will definitely be more careful with slices and array indexes in the future.
Was it a fiasco? Really? The rust unwrap call is the equivalent to C code like this:
int result = foo(…);
assert(result >= 0);
If that assert tripped, would you blame the assert? Of course not. Or blame C? No. If that assert tripped, it’s doing its job by telling you there’s a problem in the call to foo().
You can write buggy code in rust just like you can in any other language.
Funny, it's really the same thing, why Rust people say we should abandon C. Meanwhile in C, it is also common to hand out handle instead of indices precisely due to this problem.
In rust, handing out indexes isn’t that common. It’s generally bad practice because your program will end up with extra, unnecessary bounds checks. Usually we program rust just the same as in C - get a reference (pointer) to an item inside the array and pass that around. The rust compiler ensures the array isn’t modified or freed while the pointer is held. (Which is helpful, but very inconvenient at times!)
It's pretty similar, but writing `for item in container { item.do_it() }` is a lot less error prone than the C equivalent. The ha-ha-but-serious take is that once you get that snippet to compile, there's almost nothing you could ever do to break it without also making the compiler scream at you.
The same day Cloudflare had its unwrap fiasco, I found a bug in my code because of a slice that in certain cases went past the end of a vector. Switched it to use iterators and will definitely be more careful with slices and array indexes in the future.