Address review comments and fix tests

library/alloc/src/collections/binary_heap/mod.rs

@@ -656,14 +656,15 @@ impl<T: Ord, A: Allocator> BinaryHeap<T, A> {
     /// # Examples
     ///
     /// ```
+    /// #![feature(binary_heap_pop_if)]
     /// use std::collections::BinaryHeap;
     /// let mut heap = BinaryHeap::from([1, 2]);
     /// let pred = |x: &i32| *x % 2 == 0;
     ///
     /// assert_eq!(heap.pop_if(pred), Some(2));
-    /// assert_eq!(heap, BinaryHeap::from([1]));
+    /// assert_eq!(heap.as_slice(), [1]);
     /// assert_eq!(heap.pop_if(pred), None);
-    /// assert_eq!(heap, BinaryHeap::from([1]));
+    /// assert_eq!(heap.as_slice(), [1]);
     /// ```
     ///
     /// # Time complexity
@@ -671,7 +672,7 @@ impl<T: Ord, A: Allocator> BinaryHeap<T, A> {
     /// The worst case cost of `pop_if` on a heap containing *n* elements is *O*(log(*n*)).
     #[unstable(feature = "binary_heap_pop_if", issue = "151828")]
     pub fn pop_if(&mut self, predicate: impl FnOnce(&T) -> bool) -> Option<T> {
-        let first = self.data.first()?;
+        let first = self.peek()?;
         if predicate(first) { self.pop() } else { None }
     }
 

library/alloctests/lib.rs

@@ -17,7 +17,6 @@
 #![feature(allocator_api)]
 #![feature(array_into_iter_constructors)]
 #![feature(assert_matches)]
-#![feature(binary_heap_pop_if)]
 #![feature(box_vec_non_null)]
 #![feature(char_internals)]
 #![feature(const_alloc_error)]

library/alloctests/tests/collections/binary_heap.rs

@@ -145,7 +145,7 @@ fn test_pop_if() {
     while let Some(popped) = heap.pop_if(|x| *x > 2) {
         assert_eq!(popped, sorted.pop().unwrap());
     }
-    assert_eq!(heap.into_sorted_vec(), vec![1, 2]);
+    assert_eq!(heap.into_sorted_vec(), vec![0, 1, 2]);
 }
 
 #[test]

library/alloctests/tests/lib.rs

@@ -1,4 +1,5 @@
 #![feature(allocator_api)]
+#![feature(binary_heap_pop_if)]
 #![feature(const_heap)]
 #![feature(deque_extend_front)]
 #![feature(iter_array_chunks)]