for x in xs.iter_mut() -> for x in &mut xs

Also `for x in option.iter_mut()` -> `if let Some(ref mut x) = option`

Author: Jorge Aparicio

src/libcollections/bit.rs

@@ -431,7 +431,7 @@ impl Bitv {
     /// ```
     #[inline]
     pub fn set_all(&mut self) {
-        for w in self.storage.iter_mut() { *w = !0u32; }
+        for w in &mut self.storage { *w = !0u32; }
         self.fix_last_block();
     }
 
@@ -451,7 +451,7 @@ impl Bitv {
     /// ```
     #[inline]
     pub fn negate(&mut self) {
-        for w in self.storage.iter_mut() { *w = !*w; }
+        for w in &mut self.storage { *w = !*w; }
         self.fix_last_block();
     }
 
@@ -912,7 +912,7 @@ impl Bitv {
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn clear(&mut self) {
-        for w in self.storage.iter_mut() { *w = 0u32; }
+        for w in &mut self.storage { *w = 0u32; }
     }
 }
 

src/libcollections/ring_buf.rs

@@ -1869,7 +1869,7 @@ mod tests {
 
         b.iter(|| {
             let mut sum = 0;
-            for i in ring.iter_mut() {
+            for i in &mut ring {
                 sum += *i;
             }
             test::black_box(sum);

src/libcollections/slice.rs

@@ -1228,7 +1228,7 @@ impl Iterator for ElementSwaps {
                 self.sdir.swap(i, j);
 
                 // Swap the direction of each larger SizeDirection
-                for x in self.sdir.iter_mut() {
+                for x in &mut self.sdir {
                     if x.size > sd.size {
                         x.dir = match x.dir { Pos => Neg, Neg => Pos };
                     }
@@ -2356,7 +2356,7 @@ mod tests {
     #[test]
     fn test_mut_iterator() {
         let mut xs = [1, 2, 3, 4, 5];
-        for x in xs.iter_mut() {
+        for x in &mut xs {
             *x += 1;
         }
         assert!(xs == [2, 3, 4, 5, 6])
@@ -2656,15 +2656,15 @@ mod tests {
                 let left: &[_] = left;
                 assert!(left[..left.len()] == [1, 2][]);
             }
-            for p in left.iter_mut() {
+            for p in left {
                 *p += 1;
             }
 
             {
                 let right: &[_] = right;
                 assert!(right[..right.len()] == [3, 4, 5][]);
             }
-            for p in right.iter_mut() {
+            for p in right {
                 *p += 2;
             }
         }
@@ -2693,7 +2693,7 @@ mod tests {
         }
         assert_eq!(cnt, 5);
 
-        for f in v.iter_mut() {
+        for f in &mut v {
             assert!(*f == Foo);
             cnt += 1;
         }
@@ -2796,7 +2796,7 @@ mod tests {
         let mut v = [0u8, 1, 2, 3, 4, 5, 6];
         assert_eq!(v.chunks_mut(2).len(), 4);
         for (i, chunk) in v.chunks_mut(3).enumerate() {
-            for x in chunk.iter_mut() {
+            for x in chunk {
                 *x = i as u8;
             }
         }
@@ -2808,7 +2808,7 @@ mod tests {
     fn test_mut_chunks_rev() {
         let mut v = [0u8, 1, 2, 3, 4, 5, 6];
         for (i, chunk) in v.chunks_mut(3).rev().enumerate() {
-            for x in chunk.iter_mut() {
+            for x in chunk {
                 *x = i as u8;
             }
         }
@@ -2872,7 +2872,7 @@ mod bench {
 
         b.iter(|| {
             let mut i = 0;
-            for x in v.iter_mut() {
+            for x in &mut v {
                 *x = i;
                 i += 1;
             }
@@ -3006,7 +3006,7 @@ mod bench {
             unsafe {
                 v.set_len(1024);
             }
-            for x in v.iter_mut() {
+            for x in &mut v {
                 *x = 0;
             }
             v

src/libcollections/vec.rs

@@ -2022,7 +2022,7 @@ mod tests {
         {
             let slice = &mut values[2 ..];
             assert!(slice == [3, 4, 5]);
-            for p in slice.iter_mut() {
+            for p in slice {
                 *p += 2;
             }
         }
@@ -2036,7 +2036,7 @@ mod tests {
         {
             let slice = &mut values[.. 2];
             assert!(slice == [1, 2]);
-            for p in slice.iter_mut() {
+            for p in slice {
                 *p += 1;
             }
         }
@@ -2053,15 +2053,15 @@ mod tests {
                 let left: &[_] = left;
                 assert!(&left[..left.len()] == &[1, 2][]);
             }
-            for p in left.iter_mut() {
+            for p in left {
                 *p += 1;
             }
 
             {
                 let right: &[_] = right;
                 assert!(&right[..right.len()] == &[3, 4, 5][]);
             }
-            for p in right.iter_mut() {
+            for p in right {
                 *p += 2;
             }
         }
@@ -2137,7 +2137,7 @@ mod tests {
         v.push(());
         assert_eq!(v.iter_mut().count(), 4);
 
-        for &mut () in v.iter_mut() {}
+        for &mut () in &mut v {}
         unsafe { v.set_len(0); }
         assert_eq!(v.iter_mut().count(), 0);
     }

src/libcollections/vec_map.rs

@@ -924,7 +924,7 @@ mod test_map {
         assert!(m.insert(6, 10).is_none());
         assert!(m.insert(10, 11).is_none());
 
-        for (k, v) in m.iter_mut() {
+        for (k, v) in &mut m {
             *v += k as int;
         }
 

src/libcore/iter.rs

@@ -2205,7 +2205,7 @@ impl<A, B, I, U, F> Iterator for FlatMap<A, B, I, U, F> where
     #[inline]
     fn next(&mut self) -> Option<B> {
         loop {
-            for inner in self.frontiter.iter_mut() {
+            if let Some(ref mut inner) = self.frontiter {
                 for x in inner.by_ref() {
                     return Some(x)
                 }
@@ -2238,7 +2238,7 @@ impl<A, B, I, U, F> DoubleEndedIterator for FlatMap<A, B, I, U, F> where
     #[inline]
     fn next_back(&mut self) -> Option<B> {
         loop {
-            for inner in self.backiter.iter_mut() {
+            if let Some(ref mut inner) = self.backiter {
                 match inner.next_back() {
                     None => (),
                     y => return y

src/librand/chacha.rs

@@ -194,7 +194,7 @@ impl<'a> SeedableRng<&'a [u32]> for ChaChaRng {
 impl Rand for ChaChaRng {
     fn rand<R: Rng>(other: &mut R) -> ChaChaRng {
         let mut key : [u32; KEY_WORDS] = [0; KEY_WORDS];
-        for word in key.iter_mut() {
+        for word in &mut key {
             *word = other.gen();
         }
         SeedableRng::from_seed(key.as_slice())

src/librand/distributions/mod.rs

@@ -123,7 +123,7 @@ impl<'a, T: Clone> WeightedChoice<'a, T> {
         // we convert the list from individual weights to cumulative
         // weights so we can binary search. This *could* drop elements
         // with weight == 0 as an optimisation.
-        for item in items.iter_mut() {
+        for item in &mut *items {
             running_total = match running_total.checked_add(item.weight) {
                 Some(n) => n,
                 None => panic!("WeightedChoice::new called with a total weight \

src/librand/lib.rs

@@ -154,7 +154,7 @@ pub trait Rng : Sized {
         // optimisations are on.
         let mut count = 0;
         let mut num = 0;
-        for byte in dest.iter_mut() {
+        for byte in dest {
             if count == 0 {
                 // we could micro-optimise here by generating a u32 if
                 // we only need a few more bytes to fill the vector

src/librustc/lint/context.rs

@@ -329,7 +329,7 @@ macro_rules! run_lints { ($cx:expr, $f:ident, $($args:expr),*) => ({
     // Move the vector of passes out of `$cx` so that we can
     // iterate over it mutably while passing `$cx` to the methods.
     let mut passes = $cx.lints.passes.take().unwrap();
-    for obj in passes.iter_mut() {
+    for obj in &mut passes {
         obj.$f($cx, $($args),*);
     }
     $cx.lints.passes = Some(passes);