Rollup merge of #92077 - jyn514:remove-collapsed, r=GuillaumeGomez

[rust.git] / library / alloc / src / vec / mod.rs

diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs
index b6b11b75c99c9ab878e8e69550f53566619443e5..7185f3de18ade3b6ed9f7f4be7c159d0e6822e91 100644 (file)
--- a/library/alloc/src/vec/mod.rs
+++ b/library/alloc/src/vec/mod.rs
@@ -1520,49 +1520,46 @@ fn drop(&mut self) {
 
         let mut g = BackshiftOnDrop { v: self, processed_len: 0, deleted_cnt: 0, original_len };
 
-        // process_one return a bool indicates whether the processing element should be retained.
-        #[inline(always)]
-        fn process_one<F, T, A: Allocator, const DELETED: bool>(
+        fn process_loop<F, T, A: Allocator, const DELETED: bool>(
+            original_len: usize,
             f: &mut F,
             g: &mut BackshiftOnDrop<'_, T, A>,
-        ) -> bool
-        where
+        ) where
             F: FnMut(&mut T) -> bool,
         {
-            // SAFETY: Unchecked element must be valid.
-            let cur = unsafe { &mut *g.v.as_mut_ptr().add(g.processed_len) };
-            if !f(cur) {
-                // Advance early to avoid double drop if `drop_in_place` panicked.
-                g.processed_len += 1;
-                g.deleted_cnt += 1;
-                // SAFETY: We never touch this element again after dropped.
-                unsafe { ptr::drop_in_place(cur) };
-                // We already advanced the counter.
-                return false;
-            }
-            if DELETED {
-                // SAFETY: `deleted_cnt` > 0, so the hole slot must not overlap with current element.
-                // We use copy for move, and never touch this element again.
-                unsafe {
-                    let hole_slot = g.v.as_mut_ptr().add(g.processed_len - g.deleted_cnt);
-                    ptr::copy_nonoverlapping(cur, hole_slot, 1);
+            while g.processed_len != original_len {
+                // SAFETY: Unchecked element must be valid.
+                let cur = unsafe { &mut *g.v.as_mut_ptr().add(g.processed_len) };
+                if !f(cur) {
+                    // Advance early to avoid double drop if `drop_in_place` panicked.
+                    g.processed_len += 1;
+                    g.deleted_cnt += 1;
+                    // SAFETY: We never touch this element again after dropped.
+                    unsafe { ptr::drop_in_place(cur) };
+                    // We already advanced the counter.
+                    if DELETED {
+                        continue;
+                    } else {
+                        break;
+                    }
+                }
+                if DELETED {
+                    // SAFETY: `deleted_cnt` > 0, so the hole slot must not overlap with current element.
+                    // We use copy for move, and never touch this element again.
+                    unsafe {
+                        let hole_slot = g.v.as_mut_ptr().add(g.processed_len - g.deleted_cnt);
+                        ptr::copy_nonoverlapping(cur, hole_slot, 1);
+                    }
                 }
+                g.processed_len += 1;
             }
-            g.processed_len += 1;
-            return true;
         }
 
         // Stage 1: Nothing was deleted.
-        while g.processed_len != original_len {
-            if !process_one::<F, T, A, false>(&mut f, &mut g) {
-                break;
-            }
-        }
+        process_loop::<F, T, A, false>(original_len, &mut f, &mut g);
 
         // Stage 2: Some elements were deleted.
-        while g.processed_len != original_len {
-            process_one::<F, T, A, true>(&mut f, &mut g);
-        }
+        process_loop::<F, T, A, true>(original_len, &mut f, &mut g);
 
         // All item are processed. This can be optimized to `set_len` by LLVM.
         drop(g);
@@ -2686,11 +2683,11 @@ fn extend_desugared<I: Iterator<Item = T>>(&mut self, mut iterator: I) {
     /// # Examples
     ///
     /// ```
-    /// let mut v = vec![1, 2, 3];
-    /// let new = [7, 8];
-    /// let u: Vec<_> = v.splice(..2, new).collect();
-    /// assert_eq!(v, &[7, 8, 3]);
-    /// assert_eq!(u, &[1, 2]);
+    /// let mut v = vec![1, 2, 3, 4];
+    /// let new = [7, 8, 9];
+    /// let u: Vec<_> = v.splice(1..3, new).collect();
+    /// assert_eq!(v, &[1, 7, 8, 9, 4]);
+    /// assert_eq!(u, &[2, 3]);
     /// ```
     #[cfg(not(no_global_oom_handling))]
     #[inline]