1 files changed, 34 insertions, 8 deletions

diff --git a/src/liballoc/vec.rs b/src/liballoc/vec.rs
index 3fd7be06fd4..96a6399d051 100644
--- a/src/liballoc/vec.rs
+++ b/src/liballoc/vec.rs
@@ -1,3 +1,4 @@
+// ignore-tidy-filelength
 //! A contiguous growable array type with heap-allocated contents, written
 //! `Vec<T>`.
 //!
@@ -317,7 +318,7 @@ impl<T> Vec<T> {
     /// let mut vec: Vec<i32> = Vec::new();
     /// ```
     #[inline]
-    #[rustc_const_stable(feature = "const_vec_new", since = "1.32.0")]
+    #[rustc_const_stable(feature = "const_vec_new", since = "1.39.0")]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub const fn new() -> Vec<T> {
         Vec { buf: RawVec::NEW, len: 0 }
@@ -678,8 +679,9 @@ impl<T> Vec<T> {
         unsafe {
             self.shrink_to_fit();
             let buf = ptr::read(&self.buf);
+            let len = self.len();
             mem::forget(self);
-            buf.into_box()
+            buf.into_box(len).assume_init()
         }
     }
 
@@ -1377,6 +1379,7 @@ impl<T> Vec<T> {
     /// assert_eq!(vec2, [2, 3]);
     /// ```
     #[inline]
+    #[must_use = "use `.truncate()` if you don't need the other half"]
     #[stable(feature = "split_off", since = "1.4.0")]
     pub fn split_off(&mut self, at: usize) -> Self {
         assert!(at <= self.len(), "`at` out of bounds");
@@ -1659,7 +1662,7 @@ struct SetLenOnDrop<'a> {
 impl<'a> SetLenOnDrop<'a> {
     #[inline]
     fn new(len: &'a mut usize) -> Self {
-        SetLenOnDrop { local_len: *len, len: len }
+        SetLenOnDrop { local_len: *len, len }
     }
 
     #[inline]
@@ -2397,6 +2400,21 @@ impl<T: Clone> From<&mut [T]> for Vec<T> {
     }
 }
 
+#[stable(feature = "vec_from_array", since = "1.44.0")]
+impl<T, const N: usize> From<[T; N]> for Vec<T>
+where
+    [T; N]: LengthAtMost32,
+{
+    #[cfg(not(test))]
+    fn from(s: [T; N]) -> Vec<T> {
+        <[T]>::into_vec(box s)
+    }
+    #[cfg(test)]
+    fn from(s: [T; N]) -> Vec<T> {
+        crate::slice::into_vec(box s)
+    }
+}
+
 #[stable(feature = "vec_from_cow_slice", since = "1.14.0")]
 impl<'a, T> From<Cow<'a, [T]>> for Vec<T>
 where
@@ -2626,13 +2644,21 @@ impl<T: Clone> Clone for IntoIter<T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 unsafe impl<#[may_dangle] T> Drop for IntoIter<T> {
     fn drop(&mut self) {
+        struct DropGuard<'a, T>(&'a mut IntoIter<T>);
+
+        impl<T> Drop for DropGuard<'_, T> {
+            fn drop(&mut self) {
+                // RawVec handles deallocation
+                let _ = unsafe { RawVec::from_raw_parts(self.0.buf.as_ptr(), self.0.cap) };
+            }
+        }
+
+        let guard = DropGuard(self);
         // destroy the remaining elements
         unsafe {
-            ptr::drop_in_place(self.as_mut_slice());
+            ptr::drop_in_place(guard.0.as_mut_slice());
         }
-
-        // RawVec handles deallocation
-        let _ = unsafe { RawVec::from_raw_parts(self.buf.as_ptr(), self.cap) };
+        // now `guard` will be dropped and do the rest
     }
 }
 
@@ -2894,7 +2920,7 @@ where
     /// The filter test predicate.
     pred: F,
     /// A flag that indicates a panic has occurred in the filter test prodicate.
-    /// This is used as a hint in the drop implmentation to prevent consumption
+    /// This is used as a hint in the drop implementation to prevent consumption
     /// of the remainder of the `DrainFilter`. Any unprocessed items will be
     /// backshifted in the `vec`, but no further items will be dropped or
     /// tested by the filter predicate.