X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=library%2Fcore%2Fsrc%2Fiter%2Ftraits%2Fiterator.rs;h=fc4d4bff24f33f4a9d58a2953dd9ef562b75cf2b;hb=d4cf00f03d35c651b7853935309342a4905943f4;hp=bac836292f8fa836c163823280463423b12b6700;hpb=731e0bf721c1ec2c7843547e86b6157b40a437d1;p=rust.git

diff --git a/library/core/src/iter/traits/iterator.rs b/library/core/src/iter/traits/iterator.rs
index bac836292f8..fc4d4bff24f 100644
--- a/library/core/src/iter/traits/iterator.rs
+++ b/library/core/src/iter/traits/iterator.rs
@@ -66,6 +66,7 @@ fn _assert_is_object_safe(_: &dyn Iterator<Item = ()>) {}
 #[must_use = "iterators are lazy and do nothing unless consumed"]
 pub trait Iterator {
     /// The type of the elements being iterated over.
+    #[rustc_diagnostic_item = "IteratorItem"]
     #[stable(feature = "rust1", since = "1.0.0")]
     type Item;
 
@@ -803,7 +804,7 @@ fn map<B, F>(self, f: F) -> Map<Self, F>
     /// (0..5).map(|x| x * 2 + 1)
     ///       .for_each(move |x| tx.send(x).unwrap());
     ///
-    /// let v: Vec<_> =  rx.iter().collect();
+    /// let v: Vec<_> = rx.iter().collect();
     /// assert_eq!(v, vec![1, 3, 5, 7, 9]);
     /// ```
     ///
@@ -1380,8 +1381,8 @@ fn take(self, n: usize) -> Take<Self>
         Take::new(self, n)
     }
 
-    /// An iterator adapter similar to [`fold`] that holds internal state and
-    /// produces a new iterator.
+    /// An iterator adapter which, like [`fold`], holds internal state, but
+    /// unlike [`fold`], produces a new iterator.
     ///
     /// [`fold`]: Iterator::fold
     ///
@@ -1393,20 +1394,25 @@ fn take(self, n: usize) -> Take<Self>
     ///
     /// On iteration, the closure will be applied to each element of the
     /// iterator and the return value from the closure, an [`Option`], is
-    /// yielded by the iterator.
+    /// returned by the `next` method. Thus the closure can return
+    /// `Some(value)` to yield `value`, or `None` to end the iteration.
     ///
     /// # Examples
     ///
     /// Basic usage:
     ///
     /// ```
-    /// let a = [1, 2, 3];
+    /// let a = [1, 2, 3, 4];
     ///
     /// let mut iter = a.iter().scan(1, |state, &x| {
-    ///     // each iteration, we'll multiply the state by the element
+    ///     // each iteration, we'll multiply the state by the element ...
     ///     *state = *state * x;
     ///
-    ///     // then, we'll yield the negation of the state
+    ///     // ... and terminate if the state exceeds 6
+    ///     if *state > 6 {
+    ///         return None;
+    ///     }
+    ///     // ... else yield the negation of the state
     ///     Some(-*state)
     /// });
     ///
@@ -2653,7 +2659,10 @@ fn check<T>(mut f: impl FnMut(T) -> bool) -> impl FnMut((), T) -> ControlFlow<()
     /// argument is a double reference. You can see this effect in the
     /// examples below, with `&&x`.
     ///
+    /// If you need the index of the element, see [`position()`].
+    ///
     /// [`Some(element)`]: Some
+    /// [`position()`]: Iterator::position
     ///
     /// # Examples
     ///