Data update

Task/Happy-numbers/Rust/happy-numbers.rs

@@ -1,23 +1,24 @@
-#![feature(core)]
-
 fn sumsqd(mut n: i32) -> i32 {
     let mut sq = 0;
     while n > 0 {
         let d = n % 10;
-        sq += d*d;
-        n /= 10
+        sq += d * d;
+        n /= 10;
     }
     sq
 }
 
-use std::num::Int;
-fn cycle<T: Int>(a: T, f: fn(T) -> T) -> T {
+fn cycle<T, F>(a: T, f: F) -> T
+where
+    T: Copy + PartialEq,
+    F: Fn(T) -> T,
+{
     let mut t = a;
     let mut h = f(a);
 
     while t != h {
         t = f(t);
-        h = f(f(h))
+        h = f(f(h));
     }
     t
 }
@@ -27,10 +28,10 @@ fn ishappy(n: i32) -> bool {
 }
 
 fn main() {
-    let happy = std::iter::count(1, 1)
-                    .filter(|&n| ishappy(n))
-                    .take(8)
-                    .collect::<Vec<i32>>();
+    let happy: Vec<i32> = (1..)
+        .filter(|&n| ishappy(n))
+        .take(8)
+        .collect();
 
-    println!("{:?}", happy)
+    println!("{:?}", happy);
 }