Rollup merge of #135956 - GrigorenkoPV:vec_pop_off, r=dtolnay

Make `Vec::pop_if` a bit more presentable

#135488 minus stabilization.

As suggested in #135488 (comment).

r? tgross35

Author: matthiaskrgr

Diff for: library/alloc/src/vec/mod.rs

@@ -2511,9 +2511,9 @@ impl<T, A: Allocator> Vec<T, A> {
         }
     }
 
-    /// Removes and returns the last element in a vector if the predicate
+    /// Removes and returns the last element from a vector if the predicate
     /// returns `true`, or [`None`] if the predicate returns false or the vector
-    /// is empty.
+    /// is empty (the predicate will not be called in that case).
     ///
     /// # Examples
     ///
@@ -2528,12 +2528,9 @@ impl<T, A: Allocator> Vec<T, A> {
     /// assert_eq!(vec.pop_if(pred), None);
     /// ```
     #[unstable(feature = "vec_pop_if", issue = "122741")]
-    pub fn pop_if<F>(&mut self, f: F) -> Option<T>
-    where
-        F: FnOnce(&mut T) -> bool,
-    {
+    pub fn pop_if(&mut self, predicate: impl FnOnce(&mut T) -> bool) -> Option<T> {
         let last = self.last_mut()?;
-        if f(last) { self.pop() } else { None }
+        if predicate(last) { self.pop() } else { None }
     }
 
     /// Moves all the elements of `other` into `self`, leaving `other` empty.