// using_as.rs

//
// Type casting in Rust is done via the usage of the `as` operator. Please note
// that the `as` operator is not only used when type casting. It also helps with
// renaming imports.
//
// The goal is to make sure that the division does not fail to compile and
// returns the proper type.
//
// Execute `rustlings hint using_as` or use the `hint` watch subcommand for a
// hint.

// I AM NOT DONE

fn average(values: &[f64]) -> f64 {
    let total = values.iter().sum::<f64>();
    total / values.len() as f64  // 使用 as 将 usize 转换为 f64
}

fn main() {
    let values = [3.5, 0.3, 13.0, 11.7];
    println!("{}", average(&values));
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn returns_proper_type_and_value() {
        assert_eq!(average(&[3.5, 0.3, 13.0, 11.7]), 7.125);
    }
}

Author: unix-dot

exercises/conversions/using_as.rs

@@ -14,7 +14,7 @@
 
 fn average(values: &[f64]) -> f64 {
     let total = values.iter().sum::<f64>();
-    total / values.len()
+    total / values.len() as f64  // 使用 as 将 usize 转换为 f64
 }
 
 fn main() {