Kata

I wouldn't say "entirely". As a kuy8, the intended audience would still need to figure out what to do.

I wouldn't say "entirely".

I literally copy-pasted it and passed the tests, what do you mean "not entirely"?

the intended audience would still need to figure out what to do

There's no such thing as "intended audience".

Hey. Thanks for your comment. There are katas already with missing characters like ; or {, which can be autofilled by compiler. So I thought it would be a good idea to create a kata to show a first example about the lifetime concept of rust. And for a kyu 8; is it not okay to learn to work with the compiler messages?

There are katas already with missing characters like ; or {, which can be autofilled by compiler

Can you give an example that is relevant to the issue I raised?

And for a kyu 8; is it not okay to learn to work with the compiler messages?

Do you even understand why I raised this issue?

I cannot find the first kata, i solved on codewars. But it was such a task to add { to a function signature.

But i found this one: https://www.codewars.com/kata/50654ddff44f800200000004 Is this not relevant to your issue? The compiler says, what you can do to fix.

Can i extend the kata to solve your issue? This is a fundamental concept of rust to show. I want to focus on this concept, but without any need to change the function implementation code. Maybe you have a suggestion.

But i found this one: https://www.codewars.com/kata/50654ddff44f800200000004. Is this not relevant to your issue? The compiler says, what you can do to fix.

In that case, Rust is simply not the right language for this type of bugfixing problems - you can't make a meaningful kata if the compiler is giving away the exact code that you have to type in to make it work.

you can't make a meaningful kata if the compiler is giving away the exact code that you have to type in to make it work.

You are right.

I changed the signature, so the compiler does not show the solution, but helps to figure it out. And more; if you use the compiler it suggests the wrong fix at first.

That's an improvement, although I'm not sure whether I really like the fix. IMO, it'd be better if ys had a lifetime of &'b instead of an undeclared &'c, so that the task is focused solely on resolving the lifetimes problem rather than have an additional step of fixing a typo (only to arrive at the following code anyway):

fn merge<'a, 'b>(xs: &'a Vec<usize>, ys: &'b Vec<usize>) -> Vec<&'a usize> {
    xs.iter().chain(ys).collect()
}

Perhaps you could change the initial solution to make the user debug an incorrect attempt at fixing the lifetimes instead, which I think would be more interesting:

fn merge<'a, 'b, 'c: 'a + 'b>(xs: &'a Vec<usize>, ys: &'b Vec<usize>) -> Vec<&'c usize> {
    xs.iter().chain(ys).collect()
}

but that's up to you, whichever thing you choose, the original issue is okay resolve as is.

Thank you for your input. I am a beginner for rust and codewars, so i want to learn more about both while i create a kata. So i try to figure out, how to handle static lifetimes. But currently i have no clue.

@Unnamed all of the solutions you've submitted do not pass anymore; please, check whether the issue can be resolved now.