7 files changed, 12 insertions, 10 deletions
diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs
index e70e6ca0d55..abda5aefab6 100644
--- a/library/alloc/src/lib.rs
+++ b/library/alloc/src/lib.rs
@@ -122,6 +122,7 @@
 #![feature(fmt_internals)]
 #![feature(fn_traits)]
 #![feature(formatting_options)]
+#![feature(generic_atomic)]
 #![feature(hasher_prefixfree_extras)]
 #![feature(inplace_iteration)]
 #![feature(iter_advance_by)]
diff --git a/library/alloc/src/macros.rs b/library/alloc/src/macros.rs
index 214192b8c9a..1e6e2ae8c36 100644
--- a/library/alloc/src/macros.rs
+++ b/library/alloc/src/macros.rs
@@ -105,8 +105,7 @@ macro_rules! vec {
 macro_rules! format {
     ($($arg:tt)*) => {
         $crate::__export::must_use({
-            let res = $crate::fmt::format($crate::__export::format_args!($($arg)*));
-            res
+            $crate::fmt::format($crate::__export::format_args!($($arg)*))
         })
     }
 }
diff --git a/library/alloc/src/string.rs b/library/alloc/src/string.rs
index 9a161d057db..cd9e04a915a 100644
--- a/library/alloc/src/string.rs
+++ b/library/alloc/src/string.rs
@@ -1832,6 +1832,7 @@ impl String {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_stable(feature = "const_vec_string_slice", since = "1.87.0")]
     #[rustc_confusables("length", "size")]
+    #[cfg_attr(not(bootstrap), rustc_no_implicit_autorefs)]
     pub const fn len(&self) -> usize {
         self.vec.len()
     }
@@ -1851,6 +1852,7 @@ impl String {
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_stable(feature = "const_vec_string_slice", since = "1.87.0")]
+    #[cfg_attr(not(bootstrap), rustc_no_implicit_autorefs)]
     pub const fn is_empty(&self) -> bool {
         self.len() == 0
     }
diff --git a/library/alloc/src/sync.rs b/library/alloc/src/sync.rs
index aaa9aa4c547..17090925cfa 100644
--- a/library/alloc/src/sync.rs
+++ b/library/alloc/src/sync.rs
@@ -26,8 +26,8 @@ use core::pin::{Pin, PinCoerceUnsized};
 use core::ptr::{self, NonNull};
 #[cfg(not(no_global_oom_handling))]
 use core::slice::from_raw_parts_mut;
-use core::sync::atomic;
 use core::sync::atomic::Ordering::{Acquire, Relaxed, Release};
+use core::sync::atomic::{self, Atomic};
 use core::{borrow, fmt, hint};
 
 #[cfg(not(no_global_oom_handling))]
@@ -369,12 +369,12 @@ impl<T: ?Sized, A: Allocator> fmt::Debug for Weak<T, A> {
 // inner types.
 #[repr(C)]
 struct ArcInner<T: ?Sized> {
-    strong: atomic::AtomicUsize,
+    strong: Atomic<usize>,
 
     // the value usize::MAX acts as a sentinel for temporarily "locking" the
     // ability to upgrade weak pointers or downgrade strong ones; this is used
     // to avoid races in `make_mut` and `get_mut`.
-    weak: atomic::AtomicUsize,
+    weak: Atomic<usize>,
 
     data: T,
 }
@@ -2813,8 +2813,8 @@ impl<T, A: Allocator> Weak<T, A> {
 /// Helper type to allow accessing the reference counts without
 /// making any assertions about the data field.
 struct WeakInner<'a> {
-    weak: &'a atomic::AtomicUsize,
-    strong: &'a atomic::AtomicUsize,
+    weak: &'a Atomic<usize>,
+    strong: &'a Atomic<usize>,
 }
 
 impl<T: ?Sized> Weak<T> {
diff --git a/library/alloc/src/vec/into_iter.rs b/library/alloc/src/vec/into_iter.rs
index 3eee988b6c9..1af110691ba 100644
--- a/library/alloc/src/vec/into_iter.rs
+++ b/library/alloc/src/vec/into_iter.rs
@@ -168,7 +168,7 @@ impl<T, A: Allocator> IntoIter<T, A> {
 
         // SAFETY: This allocation originally came from a `Vec`, so it passes
         // all those checks. We have `this.buf` ≤ `this.ptr` ≤ `this.end`,
-        // so the `sub_ptr`s below cannot wrap, and will produce a well-formed
+        // so the `offset_from_unsigned`s below cannot wrap, and will produce a well-formed
         // range. `end` ≤ `buf + cap`, so the range will be in-bounds.
         // Taking `alloc` is ok because nothing else is going to look at it,
         // since our `Drop` impl isn't going to run so there's no more code.
diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs
index 68e4add30e5..65a83cb98ba 100644
--- a/library/alloc/src/vec/mod.rs
+++ b/library/alloc/src/vec/mod.rs
@@ -2588,7 +2588,7 @@ impl<T, A: Allocator> Vec<T, A> {
     #[inline]
     #[track_caller]
     unsafe fn append_elements(&mut self, other: *const [T]) {
-        let count = unsafe { (*other).len() };
+        let count = other.len();
         self.reserve(count);
         let len = self.len();
         unsafe { ptr::copy_nonoverlapping(other as *const T, self.as_mut_ptr().add(len), count) };
diff --git a/library/alloc/src/vec/splice.rs b/library/alloc/src/vec/splice.rs
index ca5cb17f8bf..ed1a0dda76d 100644
--- a/library/alloc/src/vec/splice.rs
+++ b/library/alloc/src/vec/splice.rs
@@ -59,7 +59,7 @@ impl<I: Iterator, A: Allocator> Drop for Splice<'_, I, A> {
         // and moving things into the final place.
         // Which means we can replace the slice::Iter with pointers that won't point to deallocated
         // memory, so that Drain::drop is still allowed to call iter.len(), otherwise it would break
-        // the ptr.sub_ptr contract.
+        // the ptr.offset_from_unsigned contract.
         self.drain.iter = (&[]).iter();
 
         unsafe {