std: Remove extra type params on iter adaptors

Now that associated types are fully implemented the iterator adaptors only need
type parameters which are associated with actual storage. All other type
parameters can either be derived from these (e.g. they are an associated type)
or can be bare on the `impl` block itself.

This is a breaking change due to the removal of type parameters on these
iterator adaptors, but code can fairly easily migrate by just deleting the
relevant type parameters for each adaptor. Other behavior should not be
affected.

Closes #21839
[breaking-change]

diff --git a/src/libcollections/btree/map.rs b/src/libcollections/btree/map.rs
index ce5e8f07be1b2e46f4bd64fe32ac63c04fa2a06f..b007f2759804501d512358c3041a058ce2d7fd5a 100644 (file)
--- a/src/libcollections/btree/map.rs
+++ b/src/libcollections/btree/map.rs
@@ -116,13 +116,13 @@ pub struct IntoIter<K, V> {
 /// An iterator over a BTreeMap's keys.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Keys<'a, K: 'a, V: 'a> {
-    inner: Map<(&'a K, &'a V), &'a K, Iter<'a, K, V>, fn((&'a K, &'a V)) -> &'a K>
+    inner: Map<Iter<'a, K, V>, fn((&'a K, &'a V)) -> &'a K>
 }
 
 /// An iterator over a BTreeMap's values.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Values<'a, K: 'a, V: 'a> {
-    inner: Map<(&'a K, &'a V), &'a V, Iter<'a, K, V>, fn((&'a K, &'a V)) -> &'a V>
+    inner: Map<Iter<'a, K, V>, fn((&'a K, &'a V)) -> &'a V>
 }
 
 /// An iterator over a sub-range of BTreeMap's entries.

diff --git a/src/libcollections/btree/set.rs b/src/libcollections/btree/set.rs
index 72d5bf6d7993297142a045e01e35b4c9ced95c52..1445db12a90d78d95ad13009b708e93ef3b06f04 100644 (file)
--- a/src/libcollections/btree/set.rs
+++ b/src/libcollections/btree/set.rs
@@ -45,40 +45,40 @@ pub struct Iter<'a, T: 'a> {
 /// An owning iterator over a BTreeSet's items.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct IntoIter<T> {
-    iter: Map<(T, ()), T, ::btree_map::IntoIter<T, ()>, fn((T, ())) -> T>
+    iter: Map<::btree_map::IntoIter<T, ()>, fn((T, ())) -> T>
 }
 
 /// An iterator over a sub-range of BTreeSet's items.
 pub struct Range<'a, T: 'a> {
-    iter: Map<(&'a T, &'a ()), &'a T, ::btree_map::Range<'a, T, ()>, fn((&'a T, &'a ())) -> &'a T>
+    iter: Map<::btree_map::Range<'a, T, ()>, fn((&'a T, &'a ())) -> &'a T>
 }
 
 /// A lazy iterator producing elements in the set difference (in-order).
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Difference<'a, T:'a> {
-    a: Peekable<&'a T, Iter<'a, T>>,
-    b: Peekable<&'a T, Iter<'a, T>>,
+    a: Peekable<Iter<'a, T>>,
+    b: Peekable<Iter<'a, T>>,
 }
 
 /// A lazy iterator producing elements in the set symmetric difference (in-order).
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct SymmetricDifference<'a, T:'a> {
-    a: Peekable<&'a T, Iter<'a, T>>,
-    b: Peekable<&'a T, Iter<'a, T>>,
+    a: Peekable<Iter<'a, T>>,
+    b: Peekable<Iter<'a, T>>,
 }
 
 /// A lazy iterator producing elements in the set intersection (in-order).
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Intersection<'a, T:'a> {
-    a: Peekable<&'a T, Iter<'a, T>>,
-    b: Peekable<&'a T, Iter<'a, T>>,
+    a: Peekable<Iter<'a, T>>,
+    b: Peekable<Iter<'a, T>>,
 }
 
 /// A lazy iterator producing elements in the set union (in-order).
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Union<'a, T:'a> {
-    a: Peekable<&'a T, Iter<'a, T>>,
-    b: Peekable<&'a T, Iter<'a, T>>,
+    a: Peekable<Iter<'a, T>>,
+    b: Peekable<Iter<'a, T>>,
 }
 
 impl<T: Ord> BTreeSet<T> {

diff --git a/src/libcollections/vec_map.rs b/src/libcollections/vec_map.rs
index f2a9bb4392cccc7935d4c19daab78caa592f7df1..b677b3613004f1ddd1faf60ca761e72597963d31 100644 (file)
--- a/src/libcollections/vec_map.rs
+++ b/src/libcollections/vec_map.rs
@@ -687,7 +687,7 @@ pub struct IterMut<'a, V:'a> {
 /// An iterator over the keys of a map.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Keys<'a, V: 'a> {
-    iter: Map<(uint, &'a V), uint, Iter<'a, V>, fn((uint, &'a V)) -> uint>
+    iter: Map<Iter<'a, V>, fn((uint, &'a V)) -> uint>
 }
 
 // FIXME(#19839) Remove in favor of `#[derive(Clone)]`
@@ -702,7 +702,7 @@ fn clone(&self) -> Keys<'a, V> {
 /// An iterator over the values of a map.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Values<'a, V: 'a> {
-    iter: Map<(uint, &'a V), &'a V, Iter<'a, V>, fn((uint, &'a V)) -> &'a V>
+    iter: Map<Iter<'a, V>, fn((uint, &'a V)) -> &'a V>
 }
 
 // FIXME(#19839) Remove in favor of `#[derive(Clone)]`
@@ -718,8 +718,6 @@ fn clone(&self) -> Values<'a, V> {
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct IntoIter<V> {
     iter: FilterMap<
-    (uint, Option<V>),
-    (uint, V),
     Enumerate<vec::IntoIter<Option<V>>>,
     fn((uint, Option<V>)) -> Option<(uint, V)>>
 }
@@ -727,8 +725,6 @@ pub struct IntoIter<V> {
 #[unstable(feature = "collections")]
 pub struct Drain<'a, V> {
     iter: FilterMap<
-    (uint, Option<V>),
-    (uint, V),
     Enumerate<vec::Drain<'a, Option<V>>>,
     fn((uint, Option<V>)) -> Option<(uint, V)>>
 }

diff --git a/src/libcore/iter.rs b/src/libcore/iter.rs
index 751b5959d8bd77fc52badaec0d6cda05031a4a94..84db07266b8473b3609ca892e76c66f1eb61c624 100644 (file)
--- a/src/libcore/iter.rs
+++ b/src/libcore/iter.rs
@@ -239,9 +239,7 @@ fn chain<U>(self, other: U) -> Chain<Self, U> where
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    fn zip<B, U>(self, other: U) -> Zip<Self, U> where
-        U: Iterator<Item=B>,
-    {
+    fn zip<U: Iterator>(self, other: U) -> Zip<Self, U> {
         Zip{a: self, b: other}
     }
 
@@ -259,7 +257,7 @@ fn zip<B, U>(self, other: U) -> Zip<Self, U> where
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    fn map<B, F>(self, f: F) -> Map<Self::Item, B, Self, F> where
+    fn map<B, F>(self, f: F) -> Map<Self, F> where
         F: FnMut(Self::Item) -> B,
     {
         Map{iter: self, f: f}
@@ -279,7 +277,7 @@ fn map<B, F>(self, f: F) -> Map<Self::Item, B, Self, F> where
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    fn filter<P>(self, predicate: P) -> Filter<Self::Item, Self, P> where
+    fn filter<P>(self, predicate: P) -> Filter<Self, P> where
         P: FnMut(&Self::Item) -> bool,
     {
         Filter{iter: self, predicate: predicate}
@@ -299,7 +297,7 @@ fn filter<P>(self, predicate: P) -> Filter<Self::Item, Self, P> where
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    fn filter_map<B, F>(self, f: F) -> FilterMap<Self::Item, B, Self, F> where
+    fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> where
         F: FnMut(Self::Item) -> Option<B>,
     {
         FilterMap { iter: self, f: f }
@@ -342,7 +340,7 @@ fn enumerate(self) -> Enumerate<Self> {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    fn peekable(self) -> Peekable<Self::Item, Self> {
+    fn peekable(self) -> Peekable<Self> {
         Peekable{iter: self, peeked: None}
     }
 
@@ -362,7 +360,7 @@ fn peekable(self) -> Peekable<Self::Item, Self> {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    fn skip_while<P>(self, predicate: P) -> SkipWhile<Self::Item, Self, P> where
+    fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> where
         P: FnMut(&Self::Item) -> bool,
     {
         SkipWhile{iter: self, flag: false, predicate: predicate}
@@ -383,7 +381,7 @@ fn skip_while<P>(self, predicate: P) -> SkipWhile<Self::Item, Self, P> where
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    fn take_while<P>(self, predicate: P) -> TakeWhile<Self::Item, Self, P> where
+    fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> where
         P: FnMut(&Self::Item) -> bool,
     {
         TakeWhile{iter: self, flag: false, predicate: predicate}
@@ -448,12 +446,8 @@ fn take(self, n: usize) -> Take<Self> {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    fn scan<St, B, F>(
-        self,
-        initial_state: St,
-        f: F,
-    ) -> Scan<Self::Item, B, Self, St, F> where
-        F: FnMut(&mut St, Self::Item) -> Option<B>,
+    fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F>
+        where F: FnMut(&mut St, Self::Item) -> Option<B>,
     {
         Scan{iter: self, f: f, state: initial_state}
     }
@@ -474,9 +468,8 @@ fn scan<St, B, F>(
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    fn flat_map<B, U, F>(self, f: F) -> FlatMap<Self::Item, B, Self, U, F> where
-        U: Iterator<Item=B>,
-        F: FnMut(Self::Item) -> U,
+    fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F>
+        where U: Iterator, F: FnMut(Self::Item) -> U,
     {
         FlatMap{iter: self, f: f, frontiter: None, backiter: None }
     }
@@ -534,7 +527,7 @@ fn fuse(self) -> Fuse<Self> {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    fn inspect<F>(self, f: F) -> Inspect<Self::Item, Self, F> where
+    fn inspect<F>(self, f: F) -> Inspect<Self, F> where
         F: FnMut(&Self::Item),
     {
         Inspect{iter: self, f: f}
@@ -1077,16 +1070,14 @@ fn len(&self) -> usize {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<I> ExactSizeIterator for Enumerate<I> where I: ExactSizeIterator {}
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, I, F> ExactSizeIterator for Inspect<A, I, F> where
-    I: ExactSizeIterator<Item=A>,
-    F: FnMut(&A),
+impl<I: ExactSizeIterator, F> ExactSizeIterator for Inspect<I, F> where
+    F: FnMut(&I::Item),
 {}
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<I> ExactSizeIterator for Rev<I> where I: ExactSizeIterator + DoubleEndedIterator {}
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, B, I, F> ExactSizeIterator for Map<A, B, I, F> where
-    I: ExactSizeIterator<Item=A>,
-    F: FnMut(A) -> B,
+impl<B, I: ExactSizeIterator, F> ExactSizeIterator for Map<I, F> where
+    F: FnMut(I::Item) -> B,
 {}
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<A, B> ExactSizeIterator for Zip<A, B> where A: ExactSizeIterator, B: ExactSizeIterator {}
@@ -1561,28 +1552,15 @@ fn idx(&mut self, index: usize) -> Option<(T, U)> {
 /// An iterator that maps the values of `iter` with `f`
 #[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 #[stable(feature = "rust1", since = "1.0.0")]
-pub struct Map<A, B, I: Iterator<Item=A>, F: FnMut(A) -> B> {
+#[derive(Clone)]
+pub struct Map<I, F> {
     iter: I,
     f: F,
 }
 
-// FIXME(#19839) Remove in favor of `#[derive(Clone)]`
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<A, B, I, F> Clone for Map<A, B, I, F> where
-    I: Clone + Iterator<Item=A>,
-    F: Clone + FnMut(A) -> B,
-{
-    fn clone(&self) -> Map<A, B, I, F> {
-        Map {
-            iter: self.iter.clone(),
-            f: self.f.clone(),
-        }
-    }
-}
-
-impl<A, B, I, F> Map<A, B, I, F> where I: Iterator<Item=A>, F: FnMut(A) -> B {
+impl<I: Iterator, F, B> Map<I, F> where F: FnMut(I::Item) -> B {
     #[inline]
-    fn do_map(&mut self, elt: Option<A>) -> Option<B> {
+    fn do_map(&mut self, elt: Option<I::Item>) -> Option<B> {
         match elt {
             Some(a) => Some((self.f)(a)),
             _ => None
@@ -1591,7 +1569,7 @@ fn do_map(&mut self, elt: Option<A>) -> Option<B> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, B, I, F> Iterator for Map<A, B, I, F> where I: Iterator<Item=A>, F: FnMut(A) -> B {
+impl<B, I: Iterator, F> Iterator for Map<I, F> where F: FnMut(I::Item) -> B {
     type Item = B;
 
     #[inline]
@@ -1607,9 +1585,8 @@ fn size_hint(&self) -> (usize, Option<usize>) {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, B, I, F> DoubleEndedIterator for Map<A, B, I, F> where
-    I: DoubleEndedIterator<Item=A>,
-    F: FnMut(A) -> B,
+impl<B, I: DoubleEndedIterator, F> DoubleEndedIterator for Map<I, F> where
+    F: FnMut(I::Item) -> B,
 {
     #[inline]
     fn next_back(&mut self) -> Option<B> {
@@ -1619,9 +1596,8 @@ fn next_back(&mut self) -> Option<B> {
 }
 
 #[unstable(feature = "core", reason = "trait is experimental")]
-impl<A, B, I, F> RandomAccessIterator for Map<A, B, I, F> where
-    I: RandomAccessIterator<Item=A>,
-    F: FnMut(A) -> B,
+impl<B, I: RandomAccessIterator, F> RandomAccessIterator for Map<I, F> where
+    F: FnMut(I::Item) -> B,
 {
     #[inline]
     fn indexable(&self) -> usize {
@@ -1638,31 +1614,18 @@ fn idx(&mut self, index: usize) -> Option<B> {
 /// An iterator that filters the elements of `iter` with `predicate`
 #[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 #[stable(feature = "rust1", since = "1.0.0")]
-pub struct Filter<A, I, P> where I: Iterator<Item=A>, P: FnMut(&A) -> bool {
+#[derive(Clone)]
+pub struct Filter<I, P> {
     iter: I,
     predicate: P,
 }
 
-// FIXME(#19839) Remove in favor of `#[derive(Clone)]`
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<A, I, P> Clone for Filter<A, I, P> where
-    I: Clone + Iterator<Item=A>,
-    P: Clone + FnMut(&A) -> bool,
-{
-    fn clone(&self) -> Filter<A, I, P> {
-        Filter {
-            iter: self.iter.clone(),
-            predicate: self.predicate.clone(),
-        }
-    }
-}
-
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, I, P> Iterator for Filter<A, I, P> where I: Iterator<Item=A>, P: FnMut(&A) -> bool {
-    type Item = A;
+impl<I: Iterator, P> Iterator for Filter<I, P> where P: FnMut(&I::Item) -> bool {
+    type Item = I::Item;
 
     #[inline]
-    fn next(&mut self) -> Option<A> {
+    fn next(&mut self) -> Option<I::Item> {
         for x in self.iter.by_ref() {
             if (self.predicate)(&x) {
                 return Some(x);
@@ -1681,12 +1644,11 @@ fn size_hint(&self) -> (usize, Option<usize>) {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, I, P> DoubleEndedIterator for Filter<A, I, P> where
-    I: DoubleEndedIterator<Item=A>,
-    P: FnMut(&A) -> bool,
+impl<I: DoubleEndedIterator, P> DoubleEndedIterator for Filter<I, P>
+    where P: FnMut(&I::Item) -> bool,
 {
     #[inline]
-    fn next_back(&mut self) -> Option<A> {
+    fn next_back(&mut self) -> Option<I::Item> {
         for x in self.iter.by_ref().rev() {
             if (self.predicate)(&x) {
                 return Some(x);
@@ -1699,29 +1661,15 @@ fn next_back(&mut self) -> Option<A> {
 /// An iterator that uses `f` to both filter and map elements from `iter`
 #[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 #[stable(feature = "rust1", since = "1.0.0")]
-pub struct FilterMap<A, B, I, F> where I: Iterator<Item=A>, F: FnMut(A) -> Option<B> {
+#[derive(Clone)]
+pub struct FilterMap<I, F> {
     iter: I,
     f: F,
 }
 
-// FIXME(#19839) Remove in favor of `#[derive(Clone)]`
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, B, I, F> Clone for FilterMap<A, B, I, F> where
-    I: Clone + Iterator<Item=A>,
-    F: Clone + FnMut(A) -> Option<B>,
-{
-    fn clone(&self) -> FilterMap<A, B, I, F> {
-        FilterMap {
-            iter: self.iter.clone(),
-            f: self.f.clone(),
-        }
-    }
-}
-
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<A, B, I, F> Iterator for FilterMap<A, B, I, F> where
-    I: Iterator<Item=A>,
-    F: FnMut(A) -> Option<B>,
+impl<B, I: Iterator, F> Iterator for FilterMap<I, F>
+    where F: FnMut(I::Item) -> Option<B>,
 {
     type Item = B;
 
@@ -1744,9 +1692,8 @@ fn size_hint(&self) -> (usize, Option<usize>) {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, B, I, F> DoubleEndedIterator for FilterMap<A, B, I, F> where
-    I: DoubleEndedIterator<Item=A>,
-    F: FnMut(A) -> Option<B>,
+impl<B, I: DoubleEndedIterator, F> DoubleEndedIterator for FilterMap<I, F>
+    where F: FnMut(I::Item) -> Option<B>,
 {
     #[inline]
     fn next_back(&mut self) -> Option<B> {
@@ -1824,20 +1771,28 @@ fn idx(&mut self, index: usize) -> Option<(usize, <I as Iterator>::Item)> {
 }
 
 /// An iterator with a `peek()` that returns an optional reference to the next element.
-#[derive(Clone)]
 #[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 #[stable(feature = "rust1", since = "1.0.0")]
-pub struct Peekable<T, I> where I: Iterator<Item=T> {
+pub struct Peekable<I: Iterator> {
     iter: I,
-    peeked: Option<T>,
+    peeked: Option<I::Item>,
+}
+
+impl<I: Iterator + Clone> Clone for Peekable<I> where I::Item: Clone {
+    fn clone(&self) -> Peekable<I> {
+        Peekable {
+            iter: self.iter.clone(),
+            peeked: self.peeked.clone(),
+        }
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T, I> Iterator for Peekable<T, I> where I: Iterator<Item=T> {
-    type Item = T;
+impl<I: Iterator> Iterator for Peekable<I> {
+    type Item = I::Item;
 
     #[inline]
-    fn next(&mut self) -> Option<T> {
+    fn next(&mut self) -> Option<I::Item> {
         if self.peeked.is_some() { self.peeked.take() }
         else { self.iter.next() }
     }
@@ -1859,14 +1814,14 @@ fn size_hint(&self) -> (usize, Option<usize>) {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T, I> ExactSizeIterator for Peekable<T, I> where I: ExactSizeIterator<Item = T> {}
+impl<I: ExactSizeIterator> ExactSizeIterator for Peekable<I> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T, I> Peekable<T, I> where I: Iterator<Item=T> {
-    /// Return a reference to the next element of the iterator with out advancing it,
-    /// or None if the iterator is exhausted.
+impl<I: Iterator> Peekable<I> {
+    /// Return a reference to the next element of the iterator with out
+    /// advancing it, or None if the iterator is exhausted.
     #[inline]
-    pub fn peek(&mut self) -> Option<&T> {
+    pub fn peek(&mut self) -> Option<&I::Item> {
         if self.peeked.is_none() {
             self.peeked = self.iter.next();
         }
@@ -1886,33 +1841,21 @@ pub fn is_empty(&mut self) -> bool {
 /// An iterator that rejects elements while `predicate` is true
 #[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 #[stable(feature = "rust1", since = "1.0.0")]
-pub struct SkipWhile<A, I, P> where I: Iterator<Item=A>, P: FnMut(&A) -> bool {
+#[derive(Clone)]
+pub struct SkipWhile<I, P> {
     iter: I,
     flag: bool,
     predicate: P,
 }
 
-// FIXME(#19839) Remove in favor of `#[derive(Clone)]`
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, I, P> Clone for SkipWhile<A, I, P> where
-    I: Clone + Iterator<Item=A>,
-    P: Clone + FnMut(&A) -> bool,
+impl<I: Iterator, P> Iterator for SkipWhile<I, P>
+    where P: FnMut(&I::Item) -> bool
 {
-    fn clone(&self) -> SkipWhile<A, I, P> {
-        SkipWhile {
-            iter: self.iter.clone(),
-            flag: self.flag,
-            predicate: self.predicate.clone(),
-        }
-    }
-}
-
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<A, I, P> Iterator for SkipWhile<A, I, P> where I: Iterator<Item=A>, P: FnMut(&A) -> bool {
-    type Item = A;
+    type Item = I::Item;
 
     #[inline]
-    fn next(&mut self) -> Option<A> {
+    fn next(&mut self) -> Option<I::Item> {
         for x in self.iter.by_ref() {
             if self.flag || !(self.predicate)(&x) {
                 self.flag = true;
@@ -1932,33 +1875,21 @@ fn size_hint(&self) -> (usize, Option<usize>) {
 /// An iterator that only accepts elements while `predicate` is true
 #[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 #[stable(feature = "rust1", since = "1.0.0")]
-pub struct TakeWhile<A, I, P> where I: Iterator<Item=A>, P: FnMut(&A) -> bool {
+#[derive(Clone)]
+pub struct TakeWhile<I, P> {
     iter: I,
     flag: bool,
     predicate: P,
 }
 
-// FIXME(#19839) Remove in favor of `#[derive(Clone)]`
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, I, P> Clone for TakeWhile<A, I, P> where
-    I: Clone + Iterator<Item=A>,
-    P: Clone + FnMut(&A) -> bool,
+impl<I: Iterator, P> Iterator for TakeWhile<I, P>
+    where P: FnMut(&I::Item) -> bool
 {
-    fn clone(&self) -> TakeWhile<A, I, P> {
-        TakeWhile {
-            iter: self.iter.clone(),
-            flag: self.flag,
-            predicate: self.predicate.clone(),
-        }
-    }
-}
-
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<A, I, P> Iterator for TakeWhile<A, I, P> where I: Iterator<Item=A>, P: FnMut(&A) -> bool {
-    type Item = A;
+    type Item = I::Item;
 
     #[inline]
-    fn next(&mut self) -> Option<A> {
+    fn next(&mut self) -> Option<I::Item> {
         if self.flag {
             None
         } else {
@@ -2118,7 +2049,8 @@ impl<I> ExactSizeIterator for Take<I> where I: ExactSizeIterator {}
 /// An iterator to maintain state while iterating another iterator
 #[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 #[stable(feature = "rust1", since = "1.0.0")]
-pub struct Scan<A, B, I, St, F> where I: Iterator, F: FnMut(&mut St, A) -> Option<B> {
+#[derive(Clone)]
+pub struct Scan<I, St, F> {
     iter: I,
     f: F,
 
@@ -2126,26 +2058,9 @@ pub struct Scan<A, B, I, St, F> where I: Iterator, F: FnMut(&mut St, A) -> Optio
     pub state: St,
 }
 
-// FIXME(#19839) Remove in favor of `#[derive(Clone)]`
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, B, I, St, F> Clone for Scan<A, B, I, St, F> where
-    I: Clone + Iterator<Item=A>,
-    St: Clone,
-    F: Clone + FnMut(&mut St, A) -> Option<B>,
-{
-    fn clone(&self) -> Scan<A, B, I, St, F> {
-        Scan {
-            iter: self.iter.clone(),
-            f: self.f.clone(),
-            state: self.state.clone(),
-        }
-    }
-}
-
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<A, B, I, St, F> Iterator for Scan<A, B, I, St, F> where
-    I: Iterator<Item=A>,
-    F: FnMut(&mut St, A) -> Option<B>,
+impl<B, I: Iterator, St, F> Iterator for Scan<I, St, F> where
+    F: FnMut(&mut St, I::Item) -> Option<B>,
 {
     type Item = B;
 
@@ -2166,44 +2081,22 @@ fn size_hint(&self) -> (usize, Option<usize>) {
 ///
 #[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 #[stable(feature = "rust1", since = "1.0.0")]
-pub struct FlatMap<A, B, I, U, F> where
-    I: Iterator<Item=A>,
-    U: Iterator<Item=B>,
-    F: FnMut(A) -> U,
-{
+#[derive(Clone)]
+pub struct FlatMap<I, U, F> {
     iter: I,
     f: F,
     frontiter: Option<U>,
     backiter: Option<U>,
 }
 
-// FIXME(#19839) Remove in favor of `#[derive(Clone)]`
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<A, B, I, U, F> Clone for FlatMap<A, B, I, U, F> where
-    I: Clone + Iterator<Item=A>,
-    U: Clone + Iterator<Item=B>,
-    F: Clone + FnMut(A) -> U,
-{
-    fn clone(&self) -> FlatMap<A, B, I, U, F> {
-        FlatMap {
-            iter: self.iter.clone(),
-            f: self.f.clone(),
-            frontiter: self.frontiter.clone(),
-            backiter: self.backiter.clone(),
-        }
-    }
-}
-
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, B, I, U, F> Iterator for FlatMap<A, B, I, U, F> where
-    I: Iterator<Item=A>,
-    U: Iterator<Item=B>,
-    F: FnMut(A) -> U,
+impl<I: Iterator, U: Iterator, F> Iterator for FlatMap<I, U, F>
+    where F: FnMut(I::Item) -> U,
 {
-    type Item = B;
+    type Item = U::Item;
 
     #[inline]
-    fn next(&mut self) -> Option<B> {
+    fn next(&mut self) -> Option<U::Item> {
         loop {
             for inner in self.frontiter.iter_mut() {
                 for x in inner.by_ref() {
@@ -2230,13 +2123,12 @@ fn size_hint(&self) -> (usize, Option<usize>) {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, B, I, U, F> DoubleEndedIterator for FlatMap<A, B, I, U, F> where
-    I: DoubleEndedIterator<Item=A>,
-    U: DoubleEndedIterator<Item=B>,
-    F: FnMut(A) -> U,
+impl<I: DoubleEndedIterator, U: DoubleEndedIterator, F> DoubleEndedIterator
+    for FlatMap<I, U, F>
+    where F: FnMut(I::Item) -> U
 {
     #[inline]
-    fn next_back(&mut self) -> Option<B> {
+    fn next_back(&mut self) -> Option<U::Item> {
         loop {
             for inner in self.backiter.iter_mut() {
                 match inner.next_back() {
@@ -2340,28 +2232,15 @@ pub fn reset_fuse(&mut self) {
 /// element before yielding it.
 #[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 #[stable(feature = "rust1", since = "1.0.0")]
-pub struct Inspect<A, I, F> where I: Iterator<Item=A>, F: FnMut(&A) {
+#[derive(Clone)]
+pub struct Inspect<I, F> {
     iter: I,
     f: F,
 }
 
-// FIXME(#19839) Remove in favor of `#[derive(Clone)]`
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<A, I, F> Clone for Inspect<A, I, F> where
-    I: Clone + Iterator<Item=A>,
-    F: Clone + FnMut(&A),
-{
-    fn clone(&self) -> Inspect<A, I, F> {
-        Inspect {
-            iter: self.iter.clone(),
-            f: self.f.clone(),
-        }
-    }
-}
-
-impl<A, I, F> Inspect<A, I, F> where I: Iterator<Item=A>, F: FnMut(&A) {
+impl<I: Iterator, F> Inspect<I, F> where F: FnMut(&I::Item) {
     #[inline]
-    fn do_inspect(&mut self, elt: Option<A>) -> Option<A> {
+    fn do_inspect(&mut self, elt: Option<I::Item>) -> Option<I::Item> {
         match elt {
             Some(ref a) => (self.f)(a),
             None => ()
@@ -2372,11 +2251,11 @@ fn do_inspect(&mut self, elt: Option<A>) -> Option<A> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, I, F> Iterator for Inspect<A, I, F> where I: Iterator<Item=A>, F: FnMut(&A) {
-    type Item = A;
+impl<I: Iterator, F> Iterator for Inspect<I, F> where F: FnMut(&I::Item) {
+    type Item = I::Item;
 
     #[inline]
-    fn next(&mut self) -> Option<A> {
+    fn next(&mut self) -> Option<I::Item> {
         let next = self.iter.next();
         self.do_inspect(next)
     }
@@ -2388,21 +2267,19 @@ fn size_hint(&self) -> (usize, Option<usize>) {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, I, F> DoubleEndedIterator for Inspect<A, I, F> where
-    I: DoubleEndedIterator<Item=A>,
-    F: FnMut(&A),
+impl<I: DoubleEndedIterator, F> DoubleEndedIterator for Inspect<I, F>
+    where F: FnMut(&I::Item),
 {
     #[inline]
-    fn next_back(&mut self) -> Option<A> {
+    fn next_back(&mut self) -> Option<I::Item> {
         let next = self.iter.next_back();
         self.do_inspect(next)
     }
 }
 
 #[unstable(feature = "core", reason = "trait is experimental")]
-impl<A, I, F> RandomAccessIterator for Inspect<A, I, F> where
-    I: RandomAccessIterator<Item=A>,
-    F: FnMut(&A),
+impl<I: RandomAccessIterator, F> RandomAccessIterator for Inspect<I, F>
+    where F: FnMut(&I::Item),
 {
     #[inline]
     fn indexable(&self) -> usize {
@@ -2410,7 +2287,7 @@ fn indexable(&self) -> usize {
     }
 
     #[inline]
-    fn idx(&mut self, index: usize) -> Option<A> {
+    fn idx(&mut self, index: usize) -> Option<I::Item> {
         let element = self.iter.idx(index);
         self.do_inspect(element)
     }
@@ -2426,9 +2303,11 @@ fn idx(&mut self, index: usize) -> Option<A> {
 /// use std::iter::Unfold;
 /// use std::num::Int; // For `.checked_add()`
 ///
-/// // This iterator will yield up to the last Fibonacci number before the max value of `u32`.
-/// // You can simply change `u32` to `u64` in this line if you want higher values than that.
-/// let mut fibonacci = Unfold::new((Some(0u32), Some(1u32)), |&mut (ref mut x2, ref mut x1)| {
+/// // This iterator will yield up to the last Fibonacci number before the max
+/// // value of `u32`. You can simply change `u32` to `u64` in this line if
+/// // you want higher values than that.
+/// let mut fibonacci = Unfold::new((Some(0u32), Some(1u32)),
+///                                 |&mut (ref mut x2, ref mut x1)| {
 ///     // Attempt to get the next Fibonacci number
 ///     // `x1` will be `None` if previously overflowed.
 ///     let next = match (*x2, *x1) {
@@ -2449,32 +2328,19 @@ fn idx(&mut self, index: usize) -> Option<A> {
 /// }
 /// ```
 #[unstable(feature = "core")]
-pub struct Unfold<A, St, F> where F: FnMut(&mut St) -> Option<A> {
+#[derive(Clone)]
+pub struct Unfold<St, F> {
     f: F,
     /// Internal state that will be passed to the closure on the next iteration
     pub state: St,
 }
 
-// FIXME(#19839) Remove in favor of `#[derive(Clone)]`
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<A, St, F> Clone for Unfold<A, St, F> where
-    F: Clone + FnMut(&mut St) -> Option<A>,
-    St: Clone,
-{
-    fn clone(&self) -> Unfold<A, St, F> {
-        Unfold {
-            f: self.f.clone(),
-            state: self.state.clone(),
-        }
-    }
-}
-
 #[unstable(feature = "core")]
-impl<A, St, F> Unfold<A, St, F> where F: FnMut(&mut St) -> Option<A> {
+impl<A, St, F> Unfold<St, F> where F: FnMut(&mut St) -> Option<A> {
     /// Creates a new iterator with the specified closure as the "iterator
     /// function" and an initial state to eventually pass to the closure
     #[inline]
-    pub fn new(initial_state: St, f: F) -> Unfold<A, St, F> {
+    pub fn new(initial_state: St, f: F) -> Unfold<St, F> {
         Unfold {
             f: f,
             state: initial_state
@@ -2483,7 +2349,7 @@ pub fn new(initial_state: St, f: F) -> Unfold<A, St, F> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<A, St, F> Iterator for Unfold<A, St, F> where F: FnMut(&mut St) -> Option<A> {
+impl<A, St, F> Iterator for Unfold<St, F> where F: FnMut(&mut St) -> Option<A> {
     type Item = A;
 
     #[inline]
@@ -2921,7 +2787,7 @@ fn idx(&mut self, _: usize) -> Option<A> { Some(self.element.clone()) }
 /// An iterator that repeatedly applies a given function, starting
 /// from a given seed value.
 #[unstable(feature = "core")]
-pub type Iterate<T, F> = Unfold<T, IterateState<T, F>, fn(&mut IterateState<T, F>) -> Option<T>>;
+pub type Iterate<T, F> = Unfold<IterateState<T, F>, fn(&mut IterateState<T, F>) -> Option<T>>;
 
 /// Create a new iterator that produces an infinite sequence of
 /// repeated applications of the given function `f`.

diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index cb7af3b3d35a1297fe73e529e2105435443b23fa..85b4a2026447f5fea648473b7ece0025366a362d 100644 (file)
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -478,7 +478,7 @@ fn next_back(&mut self) -> Option<(uint, char)> {
 /// Created with `StrExt::bytes`
 #[stable(feature = "rust1", since = "1.0.0")]
 #[derive(Clone)]
-pub struct Bytes<'a>(Map<&'a u8, u8, slice::Iter<'a, u8>, BytesDeref>);
+pub struct Bytes<'a>(Map<slice::Iter<'a, u8>, BytesDeref>);
 delegate_iter!{exact u8 : Bytes<'a>}
 
 /// A temporary fn new type that ensures that the `Bytes` iterator
@@ -526,7 +526,7 @@ pub struct Lines<'a> {
 /// An iterator over the lines of a string, separated by either `\n` or (`\r\n`).
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct LinesAny<'a> {
-    inner: Map<&'a str, &'a str, Lines<'a>, fn(&str) -> &str>,
+    inner: Map<Lines<'a>, fn(&str) -> &str>,
 }
 
 impl<'a, Sep> CharSplits<'a, Sep> {

diff --git a/src/librustc_trans/trans/basic_block.rs b/src/librustc_trans/trans/basic_block.rs
index d3ff432b5e41860f78368853928a8428eeb3d412..f11c3154274e7f741bb824532795d2e4803c6080 100644 (file)
--- a/src/librustc_trans/trans/basic_block.rs
+++ b/src/librustc_trans/trans/basic_block.rs
@@ -16,12 +16,7 @@
 #[derive(Copy)]
 pub struct BasicBlock(pub BasicBlockRef);
 
-pub type Preds = Map<
-    Value,
-    BasicBlock,
-    Filter<Value, Users, fn(&Value) -> bool>,
-    fn(Value) -> BasicBlock,
->;
+pub type Preds = Map<Filter<Users, fn(&Value) -> bool>, fn(Value) -> BasicBlock>;
 
 /// Wrapper for LLVM BasicBlockRef
 impl BasicBlock {

diff --git a/src/libstd/collections/hash/map.rs b/src/libstd/collections/hash/map.rs
index 3e2c7627dbe55c700d6d39b6097582a08a703a7d..852d5a86fc0e1dc9e2eb0e1bab34d3457097f685 100644 (file)
--- a/src/libstd/collections/hash/map.rs
+++ b/src/libstd/collections/hash/map.rs
@@ -1300,18 +1300,13 @@ pub struct IterMut<'a, K: 'a, V: 'a> {
 /// HashMap move iterator.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct IntoIter<K, V> {
-    inner: iter::Map<
-        (SafeHash, K, V),
-        (K, V),
-        table::IntoIter<K, V>,
-        fn((SafeHash, K, V)) -> (K, V),
-    >
+    inner: iter::Map<table::IntoIter<K, V>, fn((SafeHash, K, V)) -> (K, V)>
 }
 
 /// HashMap keys iterator.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Keys<'a, K: 'a, V: 'a> {
-    inner: Map<(&'a K, &'a V), &'a K, Iter<'a, K, V>, fn((&'a K, &'a V)) -> &'a K>
+    inner: Map<Iter<'a, K, V>, fn((&'a K, &'a V)) -> &'a K>
 }
 
 // FIXME(#19839) Remove in favor of `#[derive(Clone)]`
@@ -1326,7 +1321,7 @@ fn clone(&self) -> Keys<'a, K, V> {
 /// HashMap values iterator.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Values<'a, K: 'a, V: 'a> {
-    inner: Map<(&'a K, &'a V), &'a V, Iter<'a, K, V>, fn((&'a K, &'a V)) -> &'a V>
+    inner: Map<Iter<'a, K, V>, fn((&'a K, &'a V)) -> &'a V>
 }
 
 // FIXME(#19839) Remove in favor of `#[derive(Clone)]`
@@ -1342,12 +1337,7 @@ fn clone(&self) -> Values<'a, K, V> {
 #[unstable(feature = "std_misc",
            reason = "matches collection reform specification, waiting for dust to settle")]
 pub struct Drain<'a, K: 'a, V: 'a> {
-    inner: iter::Map<
-        (SafeHash, K, V),
-        (K, V),
-        table::Drain<'a, K, V>,
-        fn((SafeHash, K, V)) -> (K, V),
-    >
+    inner: iter::Map<table::Drain<'a, K, V>, fn((SafeHash, K, V)) -> (K, V)>
 }
 
 /// A view into a single occupied location in a HashMap.

diff --git a/src/libstd/collections/hash/set.rs b/src/libstd/collections/hash/set.rs
index c6dcb0d230ff7cd54783ef4ce482f5a65bbf80ec..e6b06e5ef1f873fcd411eb572c77c57670deaef7 100644 (file)
--- a/src/libstd/collections/hash/set.rs
+++ b/src/libstd/collections/hash/set.rs
@@ -794,13 +794,13 @@ pub struct Iter<'a, K: 'a> {
 /// HashSet move iterator
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct IntoIter<K> {
-    iter: Map<(K, ()), K, map::IntoIter<K, ()>, fn((K, ())) -> K>
+    iter: Map<map::IntoIter<K, ()>, fn((K, ())) -> K>
 }
 
 /// HashSet drain iterator
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Drain<'a, K: 'a> {
-    iter: Map<(K, ()), K, map::Drain<'a, K, ()>, fn((K, ())) -> K>,
+    iter: Map<map::Drain<'a, K, ()>, fn((K, ())) -> K>,
 }
 
 /// Intersection iterator

diff --git a/src/libstd/path/posix.rs b/src/libstd/path/posix.rs
index 6a0c8a930107095a6216df3f646f2ac19476ea2c..69f815e3f8b771bc4fc2bf9289d1f54554697441 100644 (file)
--- a/src/libstd/path/posix.rs
+++ b/src/libstd/path/posix.rs
@@ -31,7 +31,7 @@
 
 /// Iterator that yields successive components of a Path as Option<&str>
 pub type StrComponents<'a> =
-    Map<&'a [u8], Option<&'a str>, Components<'a>, fn(&[u8]) -> Option<&str>>;
+    Map<Components<'a>, fn(&[u8]) -> Option<&str>>;
 
 /// Represents a POSIX file path
 #[derive(Clone)]

diff --git a/src/libstd/path/windows.rs b/src/libstd/path/windows.rs
index b524b89ef9fb27b24a18bf26bccd5c90cfcbf392..750af47ff8c10448fadedf911316476ff269f661 100644 (file)
--- a/src/libstd/path/windows.rs
+++ b/src/libstd/path/windows.rs
@@ -40,11 +40,11 @@
 /// Each component is yielded as Option<&str> for compatibility with PosixPath, but
 /// every component in WindowsPath is guaranteed to be Some.
 pub type StrComponents<'a> =
-    Map<&'a str, Option<&'a str>, SplitTerminator<'a, char>, fn(&'a str) -> Option<&'a str>>;
+    Map<SplitTerminator<'a, char>, fn(&'a str) -> Option<&'a str>>;
 
 /// Iterator that yields successive components of a Path as &[u8]
 pub type Components<'a> =
-    Map<Option<&'a str>, &'a [u8], StrComponents<'a>, fn(Option<&str>) -> &[u8]>;
+    Map<StrComponents<'a>, fn(Option<&str>) -> &[u8]>;
 
 /// Represents a Windows path
 // Notes for Windows path impl:

diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index 8ac5b6e52747a32e28d251b912ddfc25ea40ef40..3e8eab39d88773b1a0a2c9f1370c9a1c2258db41 100644 (file)
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -436,7 +436,7 @@ pub fn str_lit(lit: &str) -> String {
     let error = |&: i| format!("lexer should have rejected {} at {}", lit, i);
 
     /// Eat everything up to a non-whitespace
-    fn eat<'a>(it: &mut iter::Peekable<(usize, char), str::CharIndices<'a>>) {
+    fn eat<'a>(it: &mut iter::Peekable<str::CharIndices<'a>>) {
         loop {
             match it.peek().map(|x| x.1) {
                 Some(' ') | Some('\n') | Some('\r') | Some('\t') => {
@@ -605,7 +605,7 @@ pub fn binary_lit(lit: &str) -> Rc<Vec<u8>> {
     let error = |&: i| format!("lexer should have rejected {} at {}", lit, i);
 
     /// Eat everything up to a non-whitespace
-    fn eat<'a, I: Iterator<Item=(usize, u8)>>(it: &mut iter::Peekable<(usize, u8), I>) {
+    fn eat<'a, I: Iterator<Item=(usize, u8)>>(it: &mut iter::Peekable<I>) {
         loop {
             match it.peek().map(|x| x.1) {
                 Some(b' ') | Some(b'\n') | Some(b'\r') | Some(b'\t') => {

diff --git a/src/libunicode/u_str.rs b/src/libunicode/u_str.rs
index 9a757c0c980dde279e0e2412fb6af74ac34c5906..0e3aacbc09a9afb6ed144a138ddc2c1d5ef3355e 100644 (file)
--- a/src/libunicode/u_str.rs
+++ b/src/libunicode/u_str.rs
@@ -32,7 +32,7 @@
 /// An iterator over the words of a string, separated by a sequence of whitespace
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Words<'a> {
-    inner: Filter<&'a str, Split<'a, fn(char) -> bool>, fn(&&str) -> bool>,
+    inner: Filter<Split<'a, fn(char) -> bool>, fn(&&str) -> bool>,
 }
 
 /// Methods for Unicode string slices