Fix intradoc link and update issue number

Author: Stjepan Glavina

src/libcore/iter/mod.rs

@@ -329,7 +329,7 @@ pub use self::sources::{RepeatWith, repeat_with};
 pub use self::sources::{Empty, empty};
 #[stable(feature = "iter_once", since = "1.2.0")]
 pub use self::sources::{Once, once};
-#[unstable(feature = "iter_once_with", issue = "0")]
+#[unstable(feature = "iter_once_with", issue = "57581")]
 pub use self::sources::{OnceWith, once_with};
 #[unstable(feature = "iter_unfold", issue = "55977")]
 pub use self::sources::{Unfold, unfold, Successors, successors};

src/libcore/iter/sources.rs

@@ -385,12 +385,12 @@ pub fn once<T>(value: T) -> Once<T> {
 ///
 /// [`once_with`]: fn.once_with.html
 #[derive(Copy, Clone, Debug)]
-#[unstable(feature = "iter_once_with", issue = "0")]
+#[unstable(feature = "iter_once_with", issue = "57581")]
 pub struct OnceWith<F> {
     gen: Option<F>,
 }
 
-#[unstable(feature = "iter_once_with", issue = "0")]
+#[unstable(feature = "iter_once_with", issue = "57581")]
 impl<A, F: FnOnce() -> A> Iterator for OnceWith<F> {
     type Item = A;
 
@@ -405,24 +405,24 @@ impl<A, F: FnOnce() -> A> Iterator for OnceWith<F> {
     }
 }
 
-#[unstable(feature = "iter_once_with", issue = "0")]
+#[unstable(feature = "iter_once_with", issue = "57581")]
 impl<A, F: FnOnce() -> A> DoubleEndedIterator for OnceWith<F> {
     fn next_back(&mut self) -> Option<A> {
         self.next()
     }
 }
 
-#[unstable(feature = "iter_once_with", issue = "0")]
+#[unstable(feature = "iter_once_with", issue = "57581")]
 impl<A, F: FnOnce() -> A> ExactSizeIterator for OnceWith<F> {
     fn len(&self) -> usize {
         self.gen.iter().len()
     }
 }
 
-#[unstable(feature = "iter_once_with", issue = "0")]
+#[unstable(feature = "iter_once_with", issue = "57581")]
 impl<A, F: FnOnce() -> A> FusedIterator for OnceWith<F> {}
 
-#[unstable(feature = "iter_once_with", issue = "0")]
+#[unstable(feature = "iter_once_with", issue = "57581")]
 unsafe impl<A, F: FnOnce() -> A> TrustedLen for OnceWith<F> {}
 
 /// Creates an iterator that lazily generates a value exactly once by invoking
@@ -436,6 +436,7 @@ unsafe impl<A, F: FnOnce() -> A> TrustedLen for OnceWith<F> {}
 /// Unlike [`once`], this function will lazily generate the value on request.
 ///
 /// [`once`]: fn.once.html
+/// [`chain`]: trait.Iterator.html#method.chain
 ///
 /// # Examples
 ///
@@ -480,7 +481,7 @@ unsafe impl<A, F: FnOnce() -> A> TrustedLen for OnceWith<F> {}
 /// }
 /// ```
 #[inline]
-#[unstable(feature = "iter_once_with", issue = "0")]
+#[unstable(feature = "iter_once_with", issue = "57581")]
 pub fn once_with<A, F: FnOnce() -> A>(gen: F) -> OnceWith<F> {
     OnceWith { gen: Some(gen) }
 }