Why can't I use `&Iterator` as an iterator?

Question

I have the following function that\'s supposed to find and return the longest length of a String given an Iterator:

fn max_width(st         


        

Answer 1

If you don't specifically need the generality of iterating over any given iterator, a simpler way to write the function is to have your max_width function take a &[&str] (A slice of string slices) instead. You can use a slice in a for loop because Rust knows how to turn that into an iterator (it implements IntoIterator trait):

fn max_width(strings: &[&str]) -> usize {
    let mut max_width = 0;
    for string in strings {
        if string.len() > max_width {
            max_width = string.len();
        }
    }
    return max_width;
}

fn main() {
    let strings = vec![
        "following",
        "function",
        "supposed",
        "return",
        "longest",
        "string",
        "length"
    ];

    let max_width = max_width(&strings);

    println!("Longest string had size {}", max_width);
}

// OUTPUT: Longest string had size 9

Playground here