Inclusion

[t10-13rocket]

#![allow(unused)]
// First, the struct:

fn main() {
/// An iterator which counts from one to five
struct Counter {
    count: usize,
}

// we want our count to start at one, so let's add a new() method to help.
// This isn't strictly necessary, but is convenient. Note that we start
// `count` at zero, we'll see why in `next()`'s implementation below.
impl Counter {
    fn new() -> Counter {
        Counter { count: 0 }
    }
}

// Then, we implement `Iterator` for our `Counter`:

impl Iterator for Counter {
    // we will be counting with usize
    type Item = usize;

    // next() is the only required method
    fn next(&mut self) -> Option<Self::Item> {
        // Increment our count. This is why we started at zero.
        self.count += 1;

        // Check to see if we've finished counting or not.
        if self.count < 6 {
            Some(self.count)
        } else {
            None
        }
    }
}

// And now we can use it!

let mut counter = Counter::new();

assert_eq!(counter.next(), Some(1));
assert_eq!(counter.next(), Some(2));
assert_eq!(counter.next(), Some(3));
assert_eq!(counter.next(), Some(4));
assert_eq!(counter.next(), Some(5));
assert_eq!(counter.next(), None);
}

(Playground)

Errors:

   Compiling playground v0.0.1 (/playground)
    Finished release [optimized] target(s) in 1.17s
     Running `target/release/playground`

[t10-13rocket]

Should be optional for inclusion of alphabets of all languages.

[SkiFire13]

Note that your code has a bug in release mode because self.count could overflow

[jonas-schievink]

@t10-13rocket I'm not sure what you are asking for, can you clarify?

[tesuji]

@t10-13rocket The Rust repo has issue templates that ones can fill in to help
readers understand the problem in the issue. Could you use that?

[nagisa]

Note that the code snippet is copied from the documentation of std::iter.

This issue might be spam.