From fc656262a905a50eff2be54a87295d2952d29106 Mon Sep 17 00:00:00 2001
From: Daniel Micay <danielmicay@gmail.com>
Date: Sat, 18 May 2013 04:48:22 -0400
Subject: [PATCH] iterator: use advance to implement FilterMapIterator

---
 src/libcore/iterator.rs | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/src/libcore/iterator.rs b/src/libcore/iterator.rs
index 0bf61b66f753..41f916f2d155 100644
--- a/src/libcore/iterator.rs
+++ b/src/libcore/iterator.rs
@@ -325,17 +325,13 @@ pub struct FilterMapIterator<'self, A, B, T> {
 impl<'self, A, B, T: Iterator<A>> Iterator<B> for FilterMapIterator<'self, A, B, T> {
     #[inline]
     fn next(&mut self) -> Option<B> {
-        loop {
-            match self.iter.next() {
-                None    => { return None; }
-                Some(a) => {
-                    match (self.f)(a) {
-                        Some(b) => { return Some(b); }
-                        None    => { loop; }
-                    }
-                }
+        for self.iter.advance |x| {
+            match (self.f)(x) {
+                Some(y) => return Some(y),
+                None => ()
             }
         }
+        None
     }
 }