Rollup merge of #80011 - Stupremee:stabilize-peekable-next-if, r=dtolnay

Stabilize `peekable_next_if`

This PR stabilizes the `peekable_next_if` feature

Resolves #72480

library/core/src/iter/adapters/peekable.rs

@@ -265,7 +265,6 @@ impl<I: Iterator> Peekable<I> {
     /// # Examples
     /// Consume a number if it's equal to 0.
     /// ```
-    /// #![feature(peekable_next_if)]
     /// let mut iter = (0..5).peekable();
     /// // The first item of the iterator is 0; consume it.
     /// assert_eq!(iter.next_if(|&x| x == 0), Some(0));
@@ -277,14 +276,13 @@ impl<I: Iterator> Peekable<I> {
     ///
     /// Consume any number less than 10.
     /// ```
-    /// #![feature(peekable_next_if)]
     /// let mut iter = (1..20).peekable();
     /// // Consume all numbers less than 10
     /// while iter.next_if(|&x| x < 10).is_some() {}
     /// // The next value returned will be 10
     /// assert_eq!(iter.next(), Some(10));
     /// ```
-    #[unstable(feature = "peekable_next_if", issue = "72480")]
+    #[stable(feature = "peekable_next_if", since = "1.51.0")]
     pub fn next_if(&mut self, func: impl FnOnce(&I::Item) -> bool) -> Option<I::Item> {
         match self.next() {
             Some(matched) if func(&matched) => Some(matched),
@@ -302,7 +300,6 @@ impl<I: Iterator> Peekable<I> {
     /// # Example
     /// Consume a number if it's equal to 0.
     /// ```
-    /// #![feature(peekable_next_if)]
     /// let mut iter = (0..5).peekable();
     /// // The first item of the iterator is 0; consume it.
     /// assert_eq!(iter.next_if_eq(&0), Some(0));
@@ -311,7 +308,7 @@ impl<I: Iterator> Peekable<I> {
     /// // `next_if_eq` saves the value of the next item if it was not equal to `expected`.
     /// assert_eq!(iter.next(), Some(1));
     /// ```
-    #[unstable(feature = "peekable_next_if", issue = "72480")]
+    #[stable(feature = "peekable_next_if", since = "1.51.0")]
     pub fn next_if_eq<T>(&mut self, expected: &T) -> Option<I::Item>
     where
         T: ?Sized,

library/core/tests/lib.rs

@@ -65,7 +65,6 @@
 #![feature(unwrap_infallible)]
 #![feature(option_result_unwrap_unchecked)]
 #![feature(option_unwrap_none)]
-#![feature(peekable_next_if)]
 #![feature(peekable_peek_mut)]
 #![feature(partition_point)]
 #![feature(once_cell)]

src/librustdoc/lib.rs

@@ -9,7 +9,6 @@
 #![feature(in_band_lifetimes)]
 #![feature(nll)]
 #![feature(or_patterns)]
-#![feature(peekable_next_if)]
 #![feature(test)]
 #![feature(crate_visibility_modifier)]
 #![feature(never_type)]