diff --git a/alloc/src/collections/btree/map.rs b/alloc/src/collections/btree/map.rs
index acbbb6df9a5a5..c4e599222e501 100644
--- a/alloc/src/collections/btree/map.rs
+++ b/alloc/src/collections/btree/map.rs
@@ -135,6 +135,8 @@ pub(super) const MIN_LEN: usize = node::MIN_LEN_AFTER_SPLIT;
 /// ]);
 /// ```
 ///
+/// ## `Entry` API
+///
 /// `BTreeMap` implements an [`Entry API`], which allows for complex
 /// methods of getting, setting, updating and removing keys and their values:
 ///
diff --git a/alloc/src/vec/mod.rs b/alloc/src/vec/mod.rs
index 2321aab2c516e..8001faf9d20a5 100644
--- a/alloc/src/vec/mod.rs
+++ b/alloc/src/vec/mod.rs
@@ -49,7 +49,27 @@
 //! v[1] = v[1] + 5;
 //! ```
 //!
+//! # Memory layout
+//!
+//! When the type is non-zero-sized and the capacity is nonzero, [`Vec`] uses the [`Global`]
+//! allocator for its allocation. It is valid to convert both ways between such a [`Vec`] and a raw
+//! pointer allocated with the [`Global`] allocator, provided that the [`Layout`] used with the
+//! allocator is correct for a sequence of `capacity` elements of the type, and the first `len`
+//! values pointed to by the raw pointer are valid. More precisely, a `ptr: *mut T` that has been
+//! allocated with the [`Global`] allocator with [`Layout::array::<T>(capacity)`][Layout::array] may
+//! be converted into a vec using
+//! [`Vec::<T>::from_raw_parts(ptr, len, capacity)`](Vec::from_raw_parts). Conversely, the memory
+//! backing a `value: *mut T` obtained from [`Vec::<T>::as_mut_ptr`] may be deallocated using the
+//! [`Global`] allocator with the same layout.
+//!
+//! For zero-sized types (ZSTs), or when the capacity is zero, the `Vec` pointer must be non-null
+//! and sufficiently aligned. The recommended way to build a `Vec` of ZSTs if [`vec!`] cannot be
+//! used is to use [`ptr::NonNull::dangling`].
+//!
 //! [`push`]: Vec::push
+//! [`ptr::NonNull::dangling`]: NonNull::dangling
+//! [`Layout`]: crate::alloc::Layout
+//! [Layout::array]: crate::alloc::Layout::array
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
@@ -523,18 +543,23 @@ impl<T> Vec<T> {
     /// This is highly unsafe, due to the number of invariants that aren't
     /// checked:
     ///
-    /// * `ptr` must have been allocated using the global allocator, such as via
-    ///   the [`alloc::alloc`] function.
-    /// * `T` needs to have the same alignment as what `ptr` was allocated with.
+    /// * If `T` is not a zero-sized type and the capacity is nonzero, `ptr` must have
+    ///   been allocated using the global allocator, such as via the [`alloc::alloc`]
+    ///   function. If `T` is a zero-sized type or the capacity is zero, `ptr` need
+    ///   only be non-null and aligned.
+    /// * `T` needs to have the same alignment as what `ptr` was allocated with,
+    ///   if the pointer is required to be allocated.
     ///   (`T` having a less strict alignment is not sufficient, the alignment really
     ///   needs to be equal to satisfy the [`dealloc`] requirement that memory must be
     ///   allocated and deallocated with the same layout.)
-    /// * The size of `T` times the `capacity` (ie. the allocated size in bytes) needs
-    ///   to be the same size as the pointer was allocated with. (Because similar to
-    ///   alignment, [`dealloc`] must be called with the same layout `size`.)
+    /// * The size of `T` times the `capacity` (ie. the allocated size in bytes), if
+    ///   nonzero, needs to be the same size as the pointer was allocated with.
+    ///   (Because similar to alignment, [`dealloc`] must be called with the same
+    ///   layout `size`.)
     /// * `length` needs to be less than or equal to `capacity`.
     /// * The first `length` values must be properly initialized values of type `T`.
-    /// * `capacity` needs to be the capacity that the pointer was allocated with.
+    /// * `capacity` needs to be the capacity that the pointer was allocated with,
+    ///   if the pointer is required to be allocated.
     /// * The allocated size in bytes must be no larger than `isize::MAX`.
     ///   See the safety documentation of [`pointer::offset`].
     ///
@@ -770,12 +795,16 @@ impl<T> Vec<T> {
     /// order as the arguments to [`from_raw_parts`].
     ///
     /// After calling this function, the caller is responsible for the
-    /// memory previously managed by the `Vec`. The only way to do
-    /// this is to convert the raw pointer, length, and capacity back
-    /// into a `Vec` with the [`from_raw_parts`] function, allowing
-    /// the destructor to perform the cleanup.
+    /// memory previously managed by the `Vec`. Most often, one does
+    /// this by converting the raw pointer, length, and capacity back
+    /// into a `Vec` with the [`from_raw_parts`] function; more generally,
+    /// if `T` is non-zero-sized and the capacity is nonzero, one may use
+    /// any method that calls [`dealloc`] with a layout of
+    /// `Layout::array::<T>(capacity)`; if `T` is zero-sized or the
+    /// capacity is zero, nothing needs to be done.
     ///
     /// [`from_raw_parts`]: Vec::from_raw_parts
+    /// [`dealloc`]: crate::alloc::GlobalAlloc::dealloc
     ///
     /// # Examples
     ///
@@ -1755,6 +1784,12 @@ impl<T, A: Allocator> Vec<T, A> {
     /// may still invalidate this pointer.
     /// See the second example below for how this guarantee can be used.
     ///
+    /// The method also guarantees that, as long as `T` is not zero-sized and the capacity is
+    /// nonzero, the pointer may be passed into [`dealloc`] with a layout of
+    /// `Layout::array::<T>(capacity)` in order to deallocate the backing memory. If this is done,
+    /// be careful not to run the destructor of the `Vec`, as dropping it will result in
+    /// double-frees. Wrapping the `Vec` in a [`ManuallyDrop`] is the typical way to achieve this.
+    ///
     /// # Examples
     ///
     /// ```
@@ -1787,9 +1822,24 @@ impl<T, A: Allocator> Vec<T, A> {
     /// }
     /// ```
     ///
+    /// Deallocating a vector using [`Box`] (which uses [`dealloc`] internally):
+    ///
+    /// ```
+    /// use std::mem::{ManuallyDrop, MaybeUninit};
+    ///
+    /// let mut v = ManuallyDrop::new(vec![0, 1, 2]);
+    /// let ptr = v.as_mut_ptr();
+    /// let capacity = v.capacity();
+    /// let slice_ptr: *mut [MaybeUninit<i32>] =
+    ///     std::ptr::slice_from_raw_parts_mut(ptr.cast(), capacity);
+    /// drop(unsafe { Box::from_raw(slice_ptr) });
+    /// ```
+    ///
     /// [`as_mut_ptr`]: Vec::as_mut_ptr
     /// [`as_ptr`]: Vec::as_ptr
     /// [`as_non_null`]: Vec::as_non_null
+    /// [`dealloc`]: crate::alloc::GlobalAlloc::dealloc
+    /// [`ManuallyDrop`]: core::mem::ManuallyDrop
     #[stable(feature = "vec_as_ptr", since = "1.37.0")]
     #[rustc_const_stable(feature = "const_vec_string_slice", since = "1.87.0")]
     #[rustc_never_returns_null_ptr]
diff --git a/core/src/clone.rs b/core/src/clone.rs
index e315c4fac08a2..0add77b2bc89a 100644
--- a/core/src/clone.rs
+++ b/core/src/clone.rs
@@ -139,6 +139,34 @@ mod uninit;
 /// // Note: With the manual implementations the above line will compile.
 /// ```
 ///
+/// ## `Clone` and `PartialEq`/`Eq`
+/// `Clone` is intended for the duplication of objects. Consequently, when implementing
+/// both `Clone` and [`PartialEq`], the following property is expected to hold:
+/// ```text
+/// x == x -> x.clone() == x
+/// ```
+/// In other words, if an object compares equal to itself,
+/// its clone must also compare equal to the original.
+///
+/// For types that also implement [`Eq`] – for which `x == x` always holds –
+/// this implies that `x.clone() == x` must always be true.
+/// Standard library collections such as
+/// [`HashMap`], [`HashSet`], [`BTreeMap`], [`BTreeSet`] and [`BinaryHeap`]
+/// rely on their keys respecting this property for correct behavior.
+/// Furthermore, these collections require that cloning a key preserves the outcome of the
+/// [`Hash`] and [`Ord`] methods. Thankfully, this follows automatically from `x.clone() == x`
+/// if `Hash` and `Ord` are correctly implemented according to their own requirements.
+///
+/// When deriving both `Clone` and [`PartialEq`] using `#[derive(Clone, PartialEq)]`
+/// or when additionally deriving [`Eq`] using `#[derive(Clone, PartialEq, Eq)]`,
+/// then this property is automatically upheld – provided that it is satisfied by
+/// the underlying types.
+///
+/// Violating this property is a logic error. The behavior resulting from a logic error is not
+/// specified, but users of the trait must ensure that such logic errors do *not* result in
+/// undefined behavior. This means that `unsafe` code **must not** rely on this property
+/// being satisfied.
+///
 /// ## Additional implementors
 ///
 /// In addition to the [implementors listed below][impls],
@@ -152,6 +180,11 @@ mod uninit;
 ///   (even if the referent doesn't),
 ///   while variables captured by mutable reference never implement `Clone`.
 ///
+/// [`HashMap`]: ../../std/collections/struct.HashMap.html
+/// [`HashSet`]: ../../std/collections/struct.HashSet.html
+/// [`BTreeMap`]: ../../std/collections/struct.BTreeMap.html
+/// [`BTreeSet`]: ../../std/collections/struct.BTreeSet.html
+/// [`BinaryHeap`]: ../../std/collections/struct.BinaryHeap.html
 /// [impls]: #implementors
 #[stable(feature = "rust1", since = "1.0.0")]
 #[lang = "clone"]
diff --git a/core/src/internal_macros.rs b/core/src/internal_macros.rs
index 2aaefba2468bb..f90818c7969c9 100644
--- a/core/src/internal_macros.rs
+++ b/core/src/internal_macros.rs
@@ -1,13 +1,9 @@
 // implements the unary operator "op &T"
 // based on "op T" where T is expected to be `Copy`able
 macro_rules! forward_ref_unop {
-    (impl $imp:ident, $method:ident for $t:ty) => {
-        forward_ref_unop!(impl $imp, $method for $t,
-                #[stable(feature = "rust1", since = "1.0.0")]);
-    };
-    (impl $imp:ident, $method:ident for $t:ty, #[$attr:meta]) => {
-        #[$attr]
-        impl $imp for &$t {
+    (impl $imp:ident, $method:ident for $t:ty, $(#[$attr:meta])+) => {
+        $(#[$attr])+
+        impl const $imp for &$t {
             type Output = <$t as $imp>::Output;
 
             #[inline]
@@ -21,13 +17,9 @@ macro_rules! forward_ref_unop {
 // implements binary operators "&T op U", "T op &U", "&T op &U"
 // based on "T op U" where T and U are expected to be `Copy`able
 macro_rules! forward_ref_binop {
-    (impl $imp:ident, $method:ident for $t:ty, $u:ty) => {
-        forward_ref_binop!(impl $imp, $method for $t, $u,
-                #[stable(feature = "rust1", since = "1.0.0")]);
-    };
-    (impl $imp:ident, $method:ident for $t:ty, $u:ty, #[$attr:meta]) => {
-        #[$attr]
-        impl<'a> $imp<$u> for &'a $t {
+    (impl $imp:ident, $method:ident for $t:ty, $u:ty, $(#[$attr:meta])+) => {
+        $(#[$attr])+
+        impl const $imp<$u> for &$t {
             type Output = <$t as $imp<$u>>::Output;
 
             #[inline]
@@ -37,8 +29,8 @@ macro_rules! forward_ref_binop {
             }
         }
 
-        #[$attr]
-        impl $imp<&$u> for $t {
+        $(#[$attr])+
+        impl const $imp<&$u> for $t {
             type Output = <$t as $imp<$u>>::Output;
 
             #[inline]
@@ -48,8 +40,8 @@ macro_rules! forward_ref_binop {
             }
         }
 
-        #[$attr]
-        impl $imp<&$u> for &$t {
+        $(#[$attr])+
+        impl const $imp<&$u> for &$t {
             type Output = <$t as $imp<$u>>::Output;
 
             #[inline]
@@ -64,13 +56,9 @@ macro_rules! forward_ref_binop {
 // implements "T op= &U", based on "T op= U"
 // where U is expected to be `Copy`able
 macro_rules! forward_ref_op_assign {
-    (impl $imp:ident, $method:ident for $t:ty, $u:ty) => {
-        forward_ref_op_assign!(impl $imp, $method for $t, $u,
-                #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]);
-    };
-    (impl $imp:ident, $method:ident for $t:ty, $u:ty, #[$attr:meta]) => {
-        #[$attr]
-        impl $imp<&$u> for $t {
+    (impl $imp:ident, $method:ident for $t:ty, $u:ty, $(#[$attr:meta])+) => {
+        $(#[$attr])+
+        impl const $imp<&$u> for $t {
             #[inline]
             #[track_caller]
             fn $method(&mut self, other: &$u) {
diff --git a/core/src/net/ip_addr.rs b/core/src/net/ip_addr.rs
index 6adeb2aa3fdad..87f2110034c5a 100644
--- a/core/src/net/ip_addr.rs
+++ b/core/src/net/ip_addr.rs
@@ -2,7 +2,6 @@ use super::display_buffer::DisplayBuffer;
 use crate::cmp::Ordering;
 use crate::fmt::{self, Write};
 use crate::hash::{Hash, Hasher};
-use crate::iter;
 use crate::mem::transmute;
 use crate::ops::{BitAnd, BitAndAssign, BitOr, BitOrAssign, Not};
 
@@ -2348,20 +2347,24 @@ impl const From<[u16; 8]> for IpAddr {
 }
 
 #[stable(feature = "ip_bitops", since = "1.75.0")]
-impl Not for Ipv4Addr {
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl const Not for Ipv4Addr {
     type Output = Ipv4Addr;
 
     #[inline]
     fn not(mut self) -> Ipv4Addr {
-        for octet in &mut self.octets {
-            *octet = !*octet;
+        let mut idx = 0;
+        while idx < 4 {
+            self.octets[idx] = !self.octets[idx];
+            idx += 1;
         }
         self
     }
 }
 
 #[stable(feature = "ip_bitops", since = "1.75.0")]
-impl Not for &'_ Ipv4Addr {
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl const Not for &'_ Ipv4Addr {
     type Output = Ipv4Addr;
 
     #[inline]
@@ -2371,20 +2374,24 @@ impl Not for &'_ Ipv4Addr {
 }
 
 #[stable(feature = "ip_bitops", since = "1.75.0")]
-impl Not for Ipv6Addr {
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl const Not for Ipv6Addr {
     type Output = Ipv6Addr;
 
     #[inline]
     fn not(mut self) -> Ipv6Addr {
-        for octet in &mut self.octets {
-            *octet = !*octet;
+        let mut idx = 0;
+        while idx < 16 {
+            self.octets[idx] = !self.octets[idx];
+            idx += 1;
         }
         self
     }
 }
 
 #[stable(feature = "ip_bitops", since = "1.75.0")]
-impl Not for &'_ Ipv6Addr {
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl const Not for &'_ Ipv6Addr {
     type Output = Ipv6Addr;
 
     #[inline]
@@ -2400,23 +2407,25 @@ macro_rules! bitop_impls {
     )*) => {
         $(
             $(#[$attr])*
-            impl $BitOpAssign for $ty {
+            impl const $BitOpAssign for $ty {
                 fn $bitop_assign(&mut self, rhs: $ty) {
-                    for (lhs, rhs) in iter::zip(&mut self.octets, rhs.octets) {
-                        lhs.$bitop_assign(rhs);
+                    let mut idx = 0;
+                    while idx < self.octets.len() {
+                        self.octets[idx].$bitop_assign(rhs.octets[idx]);
+                        idx += 1;
                     }
                 }
             }
 
             $(#[$attr])*
-            impl $BitOpAssign<&'_ $ty> for $ty {
+            impl const $BitOpAssign<&'_ $ty> for $ty {
                 fn $bitop_assign(&mut self, rhs: &'_ $ty) {
                     self.$bitop_assign(*rhs);
                 }
             }
 
             $(#[$attr])*
-            impl $BitOp for $ty {
+            impl const $BitOp for $ty {
                 type Output = $ty;
 
                 #[inline]
@@ -2427,7 +2436,7 @@ macro_rules! bitop_impls {
             }
 
             $(#[$attr])*
-            impl $BitOp<&'_ $ty> for $ty {
+            impl const $BitOp<&'_ $ty> for $ty {
                 type Output = $ty;
 
                 #[inline]
@@ -2438,7 +2447,7 @@ macro_rules! bitop_impls {
             }
 
             $(#[$attr])*
-            impl $BitOp<$ty> for &'_ $ty {
+            impl const $BitOp<$ty> for &'_ $ty {
                 type Output = $ty;
 
                 #[inline]
@@ -2450,7 +2459,7 @@ macro_rules! bitop_impls {
             }
 
             $(#[$attr])*
-            impl $BitOp<&'_ $ty> for &'_ $ty {
+            impl const $BitOp<&'_ $ty> for &'_ $ty {
                 type Output = $ty;
 
                 #[inline]
@@ -2466,12 +2475,16 @@ macro_rules! bitop_impls {
 
 bitop_impls! {
     #[stable(feature = "ip_bitops", since = "1.75.0")]
+    #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
     impl (BitAnd, BitAndAssign) for Ipv4Addr = (bitand, bitand_assign);
     #[stable(feature = "ip_bitops", since = "1.75.0")]
+    #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
     impl (BitOr, BitOrAssign) for Ipv4Addr = (bitor, bitor_assign);
 
     #[stable(feature = "ip_bitops", since = "1.75.0")]
+    #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
     impl (BitAnd, BitAndAssign) for Ipv6Addr = (bitand, bitand_assign);
     #[stable(feature = "ip_bitops", since = "1.75.0")]
+    #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
     impl (BitOr, BitOrAssign) for Ipv6Addr = (bitor, bitor_assign);
 }
diff --git a/core/src/num/nonzero.rs b/core/src/num/nonzero.rs
index 08a66361e6f4d..308d722f5d564 100644
--- a/core/src/num/nonzero.rs
+++ b/core/src/num/nonzero.rs
@@ -310,9 +310,10 @@ where
 }
 
 #[stable(feature = "nonzero_bitor", since = "1.45.0")]
-impl<T> BitOr for NonZero<T>
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl<T> const BitOr for NonZero<T>
 where
-    T: ZeroablePrimitive + BitOr<Output = T>,
+    T: ZeroablePrimitive + [const] BitOr<Output = T>,
 {
     type Output = Self;
 
@@ -324,9 +325,10 @@ where
 }
 
 #[stable(feature = "nonzero_bitor", since = "1.45.0")]
-impl<T> BitOr<T> for NonZero<T>
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl<T> const BitOr<T> for NonZero<T>
 where
-    T: ZeroablePrimitive + BitOr<Output = T>,
+    T: ZeroablePrimitive + [const] BitOr<Output = T>,
 {
     type Output = Self;
 
@@ -338,9 +340,10 @@ where
 }
 
 #[stable(feature = "nonzero_bitor", since = "1.45.0")]
-impl<T> BitOr<NonZero<T>> for T
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl<T> const BitOr<NonZero<T>> for T
 where
-    T: ZeroablePrimitive + BitOr<Output = T>,
+    T: ZeroablePrimitive + [const] BitOr<Output = T>,
 {
     type Output = NonZero<T>;
 
@@ -352,10 +355,11 @@ where
 }
 
 #[stable(feature = "nonzero_bitor", since = "1.45.0")]
-impl<T> BitOrAssign for NonZero<T>
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl<T> const BitOrAssign for NonZero<T>
 where
     T: ZeroablePrimitive,
-    Self: BitOr<Output = Self>,
+    Self: [const] BitOr<Output = Self>,
 {
     #[inline]
     fn bitor_assign(&mut self, rhs: Self) {
@@ -364,10 +368,11 @@ where
 }
 
 #[stable(feature = "nonzero_bitor", since = "1.45.0")]
-impl<T> BitOrAssign<T> for NonZero<T>
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl<T> const BitOrAssign<T> for NonZero<T>
 where
     T: ZeroablePrimitive,
-    Self: BitOr<T, Output = Self>,
+    Self: [const] BitOr<T, Output = Self>,
 {
     #[inline]
     fn bitor_assign(&mut self, rhs: T) {
@@ -1239,7 +1244,8 @@ macro_rules! nonzero_integer_signedness_dependent_impls {
     // Impls for unsigned nonzero types only.
     (unsigned $Int:ty) => {
         #[stable(feature = "nonzero_div", since = "1.51.0")]
-        impl Div<NonZero<$Int>> for $Int {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Div<NonZero<$Int>> for $Int {
             type Output = $Int;
 
             /// Same as `self / other.get()`, but because `other` is a `NonZero<_>`,
@@ -1257,7 +1263,8 @@ macro_rules! nonzero_integer_signedness_dependent_impls {
         }
 
         #[stable(feature = "nonzero_div_assign", since = "1.79.0")]
-        impl DivAssign<NonZero<$Int>> for $Int {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const DivAssign<NonZero<$Int>> for $Int {
             /// Same as `self /= other.get()`, but because `other` is a `NonZero<_>`,
             /// there's never a runtime check for division-by-zero.
             ///
@@ -1270,7 +1277,8 @@ macro_rules! nonzero_integer_signedness_dependent_impls {
         }
 
         #[stable(feature = "nonzero_div", since = "1.51.0")]
-        impl Rem<NonZero<$Int>> for $Int {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Rem<NonZero<$Int>> for $Int {
             type Output = $Int;
 
             /// This operation satisfies `n % d == n - (n / d) * d`, and cannot panic.
@@ -1283,7 +1291,8 @@ macro_rules! nonzero_integer_signedness_dependent_impls {
         }
 
         #[stable(feature = "nonzero_div_assign", since = "1.79.0")]
-        impl RemAssign<NonZero<$Int>> for $Int {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const RemAssign<NonZero<$Int>> for $Int {
             /// This operation satisfies `n % d == n - (n / d) * d`, and cannot panic.
             #[inline]
             fn rem_assign(&mut self, other: NonZero<$Int>) {
@@ -1323,7 +1332,8 @@ macro_rules! nonzero_integer_signedness_dependent_impls {
     // Impls for signed nonzero types only.
     (signed $Int:ty) => {
         #[stable(feature = "signed_nonzero_neg", since = "1.71.0")]
-        impl Neg for NonZero<$Int> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Neg for NonZero<$Int> {
             type Output = Self;
 
             #[inline]
@@ -1334,7 +1344,8 @@ macro_rules! nonzero_integer_signedness_dependent_impls {
         }
 
         forward_ref_unop! { impl Neg, neg for NonZero<$Int>,
-        #[stable(feature = "signed_nonzero_neg", since = "1.71.0")] }
+        #[stable(feature = "signed_nonzero_neg", since = "1.71.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     };
 }
 
diff --git a/core/src/num/saturating.rs b/core/src/num/saturating.rs
index 4460e430aecfa..c7040721b9353 100644
--- a/core/src/num/saturating.rs
+++ b/core/src/num/saturating.rs
@@ -109,7 +109,8 @@ impl<T: fmt::UpperHex> fmt::UpperHex for Saturating<T> {
 //         //         *self = *self << other;
 //         //     }
 //         // }
-//         // forward_ref_op_assign! { impl ShlAssign, shl_assign for Saturating<$t>, $f }
+//         // forward_ref_op_assign! { impl ShlAssign, shl_assign for Saturating<$t>, $f,
+//         // #[unstable(feature = "saturating_int_impl", issue = "87920")] }
 //
 //         #[unstable(feature = "saturating_int_impl", issue = "87920")]
 //         impl Shr<$f> for Saturating<$t> {
@@ -134,7 +135,8 @@ impl<T: fmt::UpperHex> fmt::UpperHex for Saturating<T> {
 //                 *self = *self >> other;
 //             }
 //         }
-//         forward_ref_op_assign! { impl ShrAssign, shr_assign for Saturating<$t>, $f }
+//         forward_ref_op_assign! { impl ShrAssign, shr_assign for Saturating<$t>, $f,
+//         #[unstable(feature = "saturating_int_impl", issue = "87920")] }
 //     };
 // }
 //
@@ -159,7 +161,8 @@ impl<T: fmt::UpperHex> fmt::UpperHex for Saturating<T> {
 //                 *self = *self << other;
 //             }
 //         }
-//         forward_ref_op_assign! { impl ShlAssign, shl_assign for Saturating<$t>, $f }
+//         forward_ref_op_assign! { impl ShlAssign, shl_assign for Saturating<$t>, $f,
+//         #[unstable(feature = "saturating_int_impl", issue = "87920")] }
 //
 //         #[unstable(feature = "saturating_int_impl", issue = "87920")]
 //         impl Shr<$f> for Saturating<$t> {
@@ -180,7 +183,8 @@ impl<T: fmt::UpperHex> fmt::UpperHex for Saturating<T> {
 //                 *self = *self >> other;
 //             }
 //         }
-//         forward_ref_op_assign! { impl ShrAssign, shr_assign for Saturating<$t>, $f }
+//         forward_ref_op_assign! { impl ShrAssign, shr_assign for Saturating<$t>, $f,
+//         #[unstable(feature = "saturating_int_impl", issue = "87920")] }
 //     };
 // }
 //
@@ -209,7 +213,8 @@ impl<T: fmt::UpperHex> fmt::UpperHex for Saturating<T> {
 macro_rules! saturating_impl {
     ($($t:ty)*) => ($(
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl Add for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Add for Saturating<$t> {
             type Output = Saturating<$t>;
 
             #[inline]
@@ -218,28 +223,36 @@ macro_rules! saturating_impl {
             }
         }
         forward_ref_binop! { impl Add, add for Saturating<$t>, Saturating<$t>,
-                #[stable(feature = "saturating_int_impl", since = "1.74.0")] }
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl AddAssign for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const AddAssign for Saturating<$t> {
             #[inline]
             fn add_assign(&mut self, other: Saturating<$t>) {
                 *self = *self + other;
             }
         }
-        forward_ref_op_assign! { impl AddAssign, add_assign for Saturating<$t>, Saturating<$t> }
+        forward_ref_op_assign! { impl AddAssign, add_assign for Saturating<$t>, Saturating<$t>,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_assign_impl", since = "1.74.0")]
-        impl AddAssign<$t> for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const AddAssign<$t> for Saturating<$t> {
             #[inline]
             fn add_assign(&mut self, other: $t) {
                 *self = *self + Saturating(other);
             }
         }
-        forward_ref_op_assign! { impl AddAssign, add_assign for Saturating<$t>, $t }
+        forward_ref_op_assign! { impl AddAssign, add_assign for Saturating<$t>, $t,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl Sub for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Sub for Saturating<$t> {
             type Output = Saturating<$t>;
 
             #[inline]
@@ -248,28 +261,36 @@ macro_rules! saturating_impl {
             }
         }
         forward_ref_binop! { impl Sub, sub for Saturating<$t>, Saturating<$t>,
-                #[stable(feature = "saturating_int_impl", since = "1.74.0")] }
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl SubAssign for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const SubAssign for Saturating<$t> {
             #[inline]
             fn sub_assign(&mut self, other: Saturating<$t>) {
                 *self = *self - other;
             }
         }
-        forward_ref_op_assign! { impl SubAssign, sub_assign for Saturating<$t>, Saturating<$t> }
+        forward_ref_op_assign! { impl SubAssign, sub_assign for Saturating<$t>, Saturating<$t>,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_assign_impl", since = "1.74.0")]
-        impl SubAssign<$t> for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const SubAssign<$t> for Saturating<$t> {
             #[inline]
             fn sub_assign(&mut self, other: $t) {
                 *self = *self - Saturating(other);
             }
         }
-        forward_ref_op_assign! { impl SubAssign, sub_assign for Saturating<$t>, $t }
+        forward_ref_op_assign! { impl SubAssign, sub_assign for Saturating<$t>, $t,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl Mul for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Mul for Saturating<$t> {
             type Output = Saturating<$t>;
 
             #[inline]
@@ -278,25 +299,32 @@ macro_rules! saturating_impl {
             }
         }
         forward_ref_binop! { impl Mul, mul for Saturating<$t>, Saturating<$t>,
-                #[stable(feature = "saturating_int_impl", since = "1.74.0")] }
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl MulAssign for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const MulAssign for Saturating<$t> {
             #[inline]
             fn mul_assign(&mut self, other: Saturating<$t>) {
                 *self = *self * other;
             }
         }
-        forward_ref_op_assign! { impl MulAssign, mul_assign for Saturating<$t>, Saturating<$t> }
+        forward_ref_op_assign! { impl MulAssign, mul_assign for Saturating<$t>, Saturating<$t>,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_assign_impl", since = "1.74.0")]
-        impl MulAssign<$t> for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const MulAssign<$t> for Saturating<$t> {
             #[inline]
             fn mul_assign(&mut self, other: $t) {
                 *self = *self * Saturating(other);
             }
         }
-        forward_ref_op_assign! { impl MulAssign, mul_assign for Saturating<$t>, $t }
+        forward_ref_op_assign! { impl MulAssign, mul_assign for Saturating<$t>, $t,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         /// # Examples
         ///
@@ -314,7 +342,8 @@ macro_rules! saturating_impl {
         #[doc = concat!("let _ = Saturating(0", stringify!($t), ") / Saturating(0);")]
         /// ```
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl Div for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Div for Saturating<$t> {
             type Output = Saturating<$t>;
 
             #[inline]
@@ -323,29 +352,36 @@ macro_rules! saturating_impl {
             }
         }
         forward_ref_binop! { impl Div, div for Saturating<$t>, Saturating<$t>,
-                #[stable(feature = "saturating_int_impl", since = "1.74.0")] }
-
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl DivAssign for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const DivAssign for Saturating<$t> {
             #[inline]
             fn div_assign(&mut self, other: Saturating<$t>) {
                 *self = *self / other;
             }
         }
-        forward_ref_op_assign! { impl DivAssign, div_assign for Saturating<$t>, Saturating<$t> }
+        forward_ref_op_assign! { impl DivAssign, div_assign for Saturating<$t>, Saturating<$t>,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_assign_impl", since = "1.74.0")]
-        impl DivAssign<$t> for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const DivAssign<$t> for Saturating<$t> {
             #[inline]
             fn div_assign(&mut self, other: $t) {
                 *self = *self / Saturating(other);
             }
         }
-        forward_ref_op_assign! { impl DivAssign, div_assign for Saturating<$t>, $t }
+        forward_ref_op_assign! { impl DivAssign, div_assign for Saturating<$t>, $t,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl Rem for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Rem for Saturating<$t> {
             type Output = Saturating<$t>;
 
             #[inline]
@@ -354,28 +390,36 @@ macro_rules! saturating_impl {
             }
         }
         forward_ref_binop! { impl Rem, rem for Saturating<$t>, Saturating<$t>,
-                #[stable(feature = "saturating_int_impl", since = "1.74.0")] }
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl RemAssign for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const RemAssign for Saturating<$t> {
             #[inline]
             fn rem_assign(&mut self, other: Saturating<$t>) {
                 *self = *self % other;
             }
         }
-        forward_ref_op_assign! { impl RemAssign, rem_assign for Saturating<$t>, Saturating<$t> }
+        forward_ref_op_assign! { impl RemAssign, rem_assign for Saturating<$t>, Saturating<$t>,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_assign_impl", since = "1.74.0")]
-        impl RemAssign<$t> for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const RemAssign<$t> for Saturating<$t> {
             #[inline]
             fn rem_assign(&mut self, other: $t) {
                 *self = *self % Saturating(other);
             }
         }
-        forward_ref_op_assign! { impl RemAssign, rem_assign for Saturating<$t>, $t }
+        forward_ref_op_assign! { impl RemAssign, rem_assign for Saturating<$t>, $t,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl Not for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Not for Saturating<$t> {
             type Output = Saturating<$t>;
 
             #[inline]
@@ -384,10 +428,12 @@ macro_rules! saturating_impl {
             }
         }
         forward_ref_unop! { impl Not, not for Saturating<$t>,
-                #[stable(feature = "saturating_int_impl", since = "1.74.0")] }
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl BitXor for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitXor for Saturating<$t> {
             type Output = Saturating<$t>;
 
             #[inline]
@@ -396,28 +442,36 @@ macro_rules! saturating_impl {
             }
         }
         forward_ref_binop! { impl BitXor, bitxor for Saturating<$t>, Saturating<$t>,
-                #[stable(feature = "saturating_int_impl", since = "1.74.0")] }
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl BitXorAssign for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitXorAssign for Saturating<$t> {
             #[inline]
             fn bitxor_assign(&mut self, other: Saturating<$t>) {
                 *self = *self ^ other;
             }
         }
-        forward_ref_op_assign! { impl BitXorAssign, bitxor_assign for Saturating<$t>, Saturating<$t> }
+        forward_ref_op_assign! { impl BitXorAssign, bitxor_assign for Saturating<$t>, Saturating<$t>,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_assign_impl", since = "1.74.0")]
-        impl BitXorAssign<$t> for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitXorAssign<$t> for Saturating<$t> {
             #[inline]
             fn bitxor_assign(&mut self, other: $t) {
                 *self = *self ^ Saturating(other);
             }
         }
-        forward_ref_op_assign! { impl BitXorAssign, bitxor_assign for Saturating<$t>, $t }
+        forward_ref_op_assign! { impl BitXorAssign, bitxor_assign for Saturating<$t>, $t,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl BitOr for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitOr for Saturating<$t> {
             type Output = Saturating<$t>;
 
             #[inline]
@@ -426,28 +480,36 @@ macro_rules! saturating_impl {
             }
         }
         forward_ref_binop! { impl BitOr, bitor for Saturating<$t>, Saturating<$t>,
-                #[stable(feature = "saturating_int_impl", since = "1.74.0")] }
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl BitOrAssign for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitOrAssign for Saturating<$t> {
             #[inline]
             fn bitor_assign(&mut self, other: Saturating<$t>) {
                 *self = *self | other;
             }
         }
-        forward_ref_op_assign! { impl BitOrAssign, bitor_assign for Saturating<$t>, Saturating<$t> }
+        forward_ref_op_assign! { impl BitOrAssign, bitor_assign for Saturating<$t>, Saturating<$t>,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_assign_impl", since = "1.74.0")]
-        impl BitOrAssign<$t> for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitOrAssign<$t> for Saturating<$t> {
             #[inline]
             fn bitor_assign(&mut self, other: $t) {
                 *self = *self | Saturating(other);
             }
         }
-        forward_ref_op_assign! { impl BitOrAssign, bitor_assign for Saturating<$t>, $t }
+        forward_ref_op_assign! { impl BitOrAssign, bitor_assign for Saturating<$t>, $t,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl BitAnd for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitAnd for Saturating<$t> {
             type Output = Saturating<$t>;
 
             #[inline]
@@ -456,25 +518,32 @@ macro_rules! saturating_impl {
             }
         }
         forward_ref_binop! { impl BitAnd, bitand for Saturating<$t>, Saturating<$t>,
-                #[stable(feature = "saturating_int_impl", since = "1.74.0")] }
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl BitAndAssign for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitAndAssign for Saturating<$t> {
             #[inline]
             fn bitand_assign(&mut self, other: Saturating<$t>) {
                 *self = *self & other;
             }
         }
-        forward_ref_op_assign! { impl BitAndAssign, bitand_assign for Saturating<$t>, Saturating<$t> }
+        forward_ref_op_assign! { impl BitAndAssign, bitand_assign for Saturating<$t>, Saturating<$t>,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "saturating_int_assign_impl", since = "1.74.0")]
-        impl BitAndAssign<$t> for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitAndAssign<$t> for Saturating<$t> {
             #[inline]
             fn bitand_assign(&mut self, other: $t) {
                 *self = *self & Saturating(other);
             }
         }
-        forward_ref_op_assign! { impl BitAndAssign, bitand_assign for Saturating<$t>, $t }
+        forward_ref_op_assign! { impl BitAndAssign, bitand_assign for Saturating<$t>, $t,
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
     )*)
 }
@@ -931,7 +1000,8 @@ macro_rules! saturating_int_impl_signed {
         }
 
         #[stable(feature = "saturating_int_impl", since = "1.74.0")]
-        impl Neg for Saturating<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Neg for Saturating<$t> {
             type Output = Self;
             #[inline]
             fn neg(self) -> Self {
@@ -939,7 +1009,8 @@ macro_rules! saturating_int_impl_signed {
             }
         }
         forward_ref_unop! { impl Neg, neg for Saturating<$t>,
-                #[stable(feature = "saturating_int_impl", since = "1.74.0")] }
+        #[stable(feature = "saturating_int_impl", since = "1.74.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )*)
 }
 
diff --git a/core/src/num/wrapping.rs b/core/src/num/wrapping.rs
index c460f38bd2e4d..9ccad4b6459cd 100644
--- a/core/src/num/wrapping.rs
+++ b/core/src/num/wrapping.rs
@@ -88,7 +88,8 @@ impl<T: fmt::UpperHex> fmt::UpperHex for Wrapping<T> {
 macro_rules! sh_impl_signed {
     ($t:ident, $f:ident) => {
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl Shl<$f> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Shl<$f> for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
             #[inline]
@@ -101,19 +102,24 @@ macro_rules! sh_impl_signed {
             }
         }
         forward_ref_binop! { impl Shl, shl for Wrapping<$t>, $f,
-        #[stable(feature = "wrapping_ref_ops", since = "1.39.0")] }
+        #[stable(feature = "wrapping_ref_ops", since = "1.39.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl ShlAssign<$f> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const ShlAssign<$f> for Wrapping<$t> {
             #[inline]
             fn shl_assign(&mut self, other: $f) {
                 *self = *self << other;
             }
         }
-        forward_ref_op_assign! { impl ShlAssign, shl_assign for Wrapping<$t>, $f }
+        forward_ref_op_assign! { impl ShlAssign, shl_assign for Wrapping<$t>, $f,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl Shr<$f> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Shr<$f> for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
             #[inline]
@@ -126,23 +132,28 @@ macro_rules! sh_impl_signed {
             }
         }
         forward_ref_binop! { impl Shr, shr for Wrapping<$t>, $f,
-        #[stable(feature = "wrapping_ref_ops", since = "1.39.0")] }
+        #[stable(feature = "wrapping_ref_ops", since = "1.39.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl ShrAssign<$f> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const ShrAssign<$f> for Wrapping<$t> {
             #[inline]
             fn shr_assign(&mut self, other: $f) {
                 *self = *self >> other;
             }
         }
-        forward_ref_op_assign! { impl ShrAssign, shr_assign for Wrapping<$t>, $f }
+        forward_ref_op_assign! { impl ShrAssign, shr_assign for Wrapping<$t>, $f,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     };
 }
 
 macro_rules! sh_impl_unsigned {
     ($t:ident, $f:ident) => {
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl Shl<$f> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Shl<$f> for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
             #[inline]
@@ -151,19 +162,24 @@ macro_rules! sh_impl_unsigned {
             }
         }
         forward_ref_binop! { impl Shl, shl for Wrapping<$t>, $f,
-        #[stable(feature = "wrapping_ref_ops", since = "1.39.0")] }
+        #[stable(feature = "wrapping_ref_ops", since = "1.39.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl ShlAssign<$f> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const ShlAssign<$f> for Wrapping<$t> {
             #[inline]
             fn shl_assign(&mut self, other: $f) {
                 *self = *self << other;
             }
         }
-        forward_ref_op_assign! { impl ShlAssign, shl_assign for Wrapping<$t>, $f }
+        forward_ref_op_assign! { impl ShlAssign, shl_assign for Wrapping<$t>, $f,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl Shr<$f> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Shr<$f> for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
             #[inline]
@@ -172,16 +188,20 @@ macro_rules! sh_impl_unsigned {
             }
         }
         forward_ref_binop! { impl Shr, shr for Wrapping<$t>, $f,
-        #[stable(feature = "wrapping_ref_ops", since = "1.39.0")] }
+        #[stable(feature = "wrapping_ref_ops", since = "1.39.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl ShrAssign<$f> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const ShrAssign<$f> for Wrapping<$t> {
             #[inline]
             fn shr_assign(&mut self, other: $f) {
                 *self = *self >> other;
             }
         }
-        forward_ref_op_assign! { impl ShrAssign, shr_assign for Wrapping<$t>, $f }
+        forward_ref_op_assign! { impl ShrAssign, shr_assign for Wrapping<$t>, $f,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     };
 }
 
@@ -210,7 +230,8 @@ sh_impl_all! { u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize }
 macro_rules! wrapping_impl {
     ($($t:ty)*) => ($(
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl Add for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Add for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
             #[inline]
@@ -219,28 +240,36 @@ macro_rules! wrapping_impl {
             }
         }
         forward_ref_binop! { impl Add, add for Wrapping<$t>, Wrapping<$t>,
-                #[stable(feature = "wrapping_ref", since = "1.14.0")] }
+        #[stable(feature = "wrapping_ref", since = "1.14.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl AddAssign for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const AddAssign for Wrapping<$t> {
             #[inline]
             fn add_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self + other;
             }
         }
-        forward_ref_op_assign! { impl AddAssign, add_assign for Wrapping<$t>, Wrapping<$t> }
+        forward_ref_op_assign! { impl AddAssign, add_assign for Wrapping<$t>, Wrapping<$t>,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")]
-        impl AddAssign<$t> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const AddAssign<$t> for Wrapping<$t> {
             #[inline]
             fn add_assign(&mut self, other: $t) {
                 *self = *self + Wrapping(other);
             }
         }
-        forward_ref_op_assign! { impl AddAssign, add_assign for Wrapping<$t>, $t }
+        forward_ref_op_assign! { impl AddAssign, add_assign for Wrapping<$t>, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl Sub for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Sub for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
             #[inline]
@@ -249,28 +278,36 @@ macro_rules! wrapping_impl {
             }
         }
         forward_ref_binop! { impl Sub, sub for Wrapping<$t>, Wrapping<$t>,
-                #[stable(feature = "wrapping_ref", since = "1.14.0")] }
+        #[stable(feature = "wrapping_ref", since = "1.14.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl SubAssign for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const SubAssign for Wrapping<$t> {
             #[inline]
             fn sub_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self - other;
             }
         }
-        forward_ref_op_assign! { impl SubAssign, sub_assign for Wrapping<$t>, Wrapping<$t> }
+        forward_ref_op_assign! { impl SubAssign, sub_assign for Wrapping<$t>, Wrapping<$t>,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")]
-        impl SubAssign<$t> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const SubAssign<$t> for Wrapping<$t> {
             #[inline]
             fn sub_assign(&mut self, other: $t) {
                 *self = *self - Wrapping(other);
             }
         }
-        forward_ref_op_assign! { impl SubAssign, sub_assign for Wrapping<$t>, $t }
+        forward_ref_op_assign! { impl SubAssign, sub_assign for Wrapping<$t>, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl Mul for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Mul for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
             #[inline]
@@ -279,28 +316,36 @@ macro_rules! wrapping_impl {
             }
         }
         forward_ref_binop! { impl Mul, mul for Wrapping<$t>, Wrapping<$t>,
-                #[stable(feature = "wrapping_ref", since = "1.14.0")] }
+        #[stable(feature = "wrapping_ref", since = "1.14.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl MulAssign for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const MulAssign for Wrapping<$t> {
             #[inline]
             fn mul_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self * other;
             }
         }
-        forward_ref_op_assign! { impl MulAssign, mul_assign for Wrapping<$t>, Wrapping<$t> }
+        forward_ref_op_assign! { impl MulAssign, mul_assign for Wrapping<$t>, Wrapping<$t>,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")]
-        impl MulAssign<$t> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const MulAssign<$t> for Wrapping<$t> {
             #[inline]
             fn mul_assign(&mut self, other: $t) {
                 *self = *self * Wrapping(other);
             }
         }
-        forward_ref_op_assign! { impl MulAssign, mul_assign for Wrapping<$t>, $t }
+        forward_ref_op_assign! { impl MulAssign, mul_assign for Wrapping<$t>, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "wrapping_div", since = "1.3.0")]
-        impl Div for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Div for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
             #[inline]
@@ -309,28 +354,36 @@ macro_rules! wrapping_impl {
             }
         }
         forward_ref_binop! { impl Div, div for Wrapping<$t>, Wrapping<$t>,
-                #[stable(feature = "wrapping_ref", since = "1.14.0")] }
+        #[stable(feature = "wrapping_ref", since = "1.14.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl DivAssign for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const DivAssign for Wrapping<$t> {
             #[inline]
             fn div_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self / other;
             }
         }
-        forward_ref_op_assign! { impl DivAssign, div_assign for Wrapping<$t>, Wrapping<$t> }
+        forward_ref_op_assign! { impl DivAssign, div_assign for Wrapping<$t>, Wrapping<$t>,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")]
-        impl DivAssign<$t> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const DivAssign<$t> for Wrapping<$t> {
             #[inline]
             fn div_assign(&mut self, other: $t) {
                 *self = *self / Wrapping(other);
             }
         }
-        forward_ref_op_assign! { impl DivAssign, div_assign for Wrapping<$t>, $t }
+        forward_ref_op_assign! { impl DivAssign, div_assign for Wrapping<$t>, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "wrapping_impls", since = "1.7.0")]
-        impl Rem for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Rem for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
             #[inline]
@@ -339,28 +392,36 @@ macro_rules! wrapping_impl {
             }
         }
         forward_ref_binop! { impl Rem, rem for Wrapping<$t>, Wrapping<$t>,
-                #[stable(feature = "wrapping_ref", since = "1.14.0")] }
+        #[stable(feature = "wrapping_ref", since = "1.14.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl RemAssign for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const RemAssign for Wrapping<$t> {
             #[inline]
             fn rem_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self % other;
             }
         }
-        forward_ref_op_assign! { impl RemAssign, rem_assign for Wrapping<$t>, Wrapping<$t> }
+        forward_ref_op_assign! { impl RemAssign, rem_assign for Wrapping<$t>, Wrapping<$t>,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")]
-        impl RemAssign<$t> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const RemAssign<$t> for Wrapping<$t> {
             #[inline]
             fn rem_assign(&mut self, other: $t) {
                 *self = *self % Wrapping(other);
             }
         }
-        forward_ref_op_assign! { impl RemAssign, rem_assign for Wrapping<$t>, $t }
+        forward_ref_op_assign! { impl RemAssign, rem_assign for Wrapping<$t>, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl Not for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Not for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
             #[inline]
@@ -369,10 +430,12 @@ macro_rules! wrapping_impl {
             }
         }
         forward_ref_unop! { impl Not, not for Wrapping<$t>,
-                #[stable(feature = "wrapping_ref", since = "1.14.0")] }
+        #[stable(feature = "wrapping_ref", since = "1.14.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl BitXor for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitXor for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
             #[inline]
@@ -381,28 +444,36 @@ macro_rules! wrapping_impl {
             }
         }
         forward_ref_binop! { impl BitXor, bitxor for Wrapping<$t>, Wrapping<$t>,
-                #[stable(feature = "wrapping_ref", since = "1.14.0")] }
+        #[stable(feature = "wrapping_ref", since = "1.14.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl BitXorAssign for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitXorAssign for Wrapping<$t> {
             #[inline]
             fn bitxor_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self ^ other;
             }
         }
-        forward_ref_op_assign! { impl BitXorAssign, bitxor_assign for Wrapping<$t>, Wrapping<$t> }
+        forward_ref_op_assign! { impl BitXorAssign, bitxor_assign for Wrapping<$t>, Wrapping<$t>,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")]
-        impl BitXorAssign<$t> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitXorAssign<$t> for Wrapping<$t> {
             #[inline]
             fn bitxor_assign(&mut self, other: $t) {
                 *self = *self ^ Wrapping(other);
             }
         }
-        forward_ref_op_assign! { impl BitXorAssign, bitxor_assign for Wrapping<$t>, $t }
+        forward_ref_op_assign! { impl BitXorAssign, bitxor_assign for Wrapping<$t>, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl BitOr for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitOr for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
             #[inline]
@@ -411,28 +482,36 @@ macro_rules! wrapping_impl {
             }
         }
         forward_ref_binop! { impl BitOr, bitor for Wrapping<$t>, Wrapping<$t>,
-                #[stable(feature = "wrapping_ref", since = "1.14.0")] }
+        #[stable(feature = "wrapping_ref", since = "1.14.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl BitOrAssign for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitOrAssign for Wrapping<$t> {
             #[inline]
             fn bitor_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self | other;
             }
         }
-        forward_ref_op_assign! { impl BitOrAssign, bitor_assign for Wrapping<$t>, Wrapping<$t> }
+        forward_ref_op_assign! { impl BitOrAssign, bitor_assign for Wrapping<$t>, Wrapping<$t>,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")]
-        impl BitOrAssign<$t> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitOrAssign<$t> for Wrapping<$t> {
             #[inline]
             fn bitor_assign(&mut self, other: $t) {
                 *self = *self | Wrapping(other);
             }
         }
-        forward_ref_op_assign! { impl BitOrAssign, bitor_assign for Wrapping<$t>, $t }
+        forward_ref_op_assign! { impl BitOrAssign, bitor_assign for Wrapping<$t>, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl BitAnd for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitAnd for Wrapping<$t> {
             type Output = Wrapping<$t>;
 
             #[inline]
@@ -441,28 +520,36 @@ macro_rules! wrapping_impl {
             }
         }
         forward_ref_binop! { impl BitAnd, bitand for Wrapping<$t>, Wrapping<$t>,
-                #[stable(feature = "wrapping_ref", since = "1.14.0")] }
+        #[stable(feature = "wrapping_ref", since = "1.14.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl BitAndAssign for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitAndAssign for Wrapping<$t> {
             #[inline]
             fn bitand_assign(&mut self, other: Wrapping<$t>) {
                 *self = *self & other;
             }
         }
-        forward_ref_op_assign! { impl BitAndAssign, bitand_assign for Wrapping<$t>, Wrapping<$t> }
+        forward_ref_op_assign! { impl BitAndAssign, bitand_assign for Wrapping<$t>, Wrapping<$t>,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")]
-        impl BitAndAssign<$t> for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitAndAssign<$t> for Wrapping<$t> {
             #[inline]
             fn bitand_assign(&mut self, other: $t) {
                 *self = *self & Wrapping(other);
             }
         }
-        forward_ref_op_assign! { impl BitAndAssign, bitand_assign for Wrapping<$t>, $t }
+        forward_ref_op_assign! { impl BitAndAssign, bitand_assign for Wrapping<$t>, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
         #[stable(feature = "wrapping_neg", since = "1.10.0")]
-        impl Neg for Wrapping<$t> {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Neg for Wrapping<$t> {
             type Output = Self;
             #[inline]
             fn neg(self) -> Self {
@@ -470,7 +557,8 @@ macro_rules! wrapping_impl {
             }
         }
         forward_ref_unop! { impl Neg, neg for Wrapping<$t>,
-                #[stable(feature = "wrapping_ref", since = "1.14.0")] }
+        #[stable(feature = "wrapping_ref", since = "1.14.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
 
     )*)
 }
diff --git a/core/src/ops/arith.rs b/core/src/ops/arith.rs
index 7d44b1733b9c6..16c719b0c3946 100644
--- a/core/src/ops/arith.rs
+++ b/core/src/ops/arith.rs
@@ -106,7 +106,9 @@ macro_rules! add_impl {
             fn add(self, other: $t) -> $t { self + other }
         }
 
-        forward_ref_binop! { impl Add, add for $t, $t }
+        forward_ref_binop! { impl Add, add for $t, $t,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )*)
 }
 
@@ -218,7 +220,9 @@ macro_rules! sub_impl {
             fn sub(self, other: $t) -> $t { self - other }
         }
 
-        forward_ref_binop! { impl Sub, sub for $t, $t }
+        forward_ref_binop! { impl Sub, sub for $t, $t,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )*)
 }
 
@@ -351,7 +355,9 @@ macro_rules! mul_impl {
             fn mul(self, other: $t) -> $t { self * other }
         }
 
-        forward_ref_binop! { impl Mul, mul for $t, $t }
+        forward_ref_binop! { impl Mul, mul for $t, $t,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )*)
 }
 
@@ -493,7 +499,9 @@ macro_rules! div_impl_integer {
             fn div(self, other: $t) -> $t { self / other }
         }
 
-        forward_ref_binop! { impl Div, div for $t, $t }
+        forward_ref_binop! { impl Div, div for $t, $t,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )*)*)
 }
 
@@ -513,7 +521,9 @@ macro_rules! div_impl_float {
             fn div(self, other: $t) -> $t { self / other }
         }
 
-        forward_ref_binop! { impl Div, div for $t, $t }
+        forward_ref_binop! { impl Div, div for $t, $t,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )*)
 }
 
@@ -599,7 +609,9 @@ macro_rules! rem_impl_integer {
             fn rem(self, other: $t) -> $t { self % other }
         }
 
-        forward_ref_binop! { impl Rem, rem for $t, $t }
+        forward_ref_binop! { impl Rem, rem for $t, $t,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )*)*)
 }
 
@@ -634,7 +646,9 @@ macro_rules! rem_impl_float {
             fn rem(self, other: $t) -> $t { self % other }
         }
 
-        forward_ref_binop! { impl Rem, rem for $t, $t }
+        forward_ref_binop! { impl Rem, rem for $t, $t,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )*)
 }
 
@@ -678,7 +692,9 @@ rem_impl_float! { f16 f32 f64 f128 }
 /// ```
 #[lang = "neg"]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[doc(alias = "-")]
+#[const_trait]
 pub trait Neg {
     /// The resulting type after applying the `-` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -701,7 +717,8 @@ pub trait Neg {
 macro_rules! neg_impl {
     ($($t:ty)*) => ($(
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl Neg for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Neg for $t {
             type Output = $t;
 
             #[inline]
@@ -709,7 +726,9 @@ macro_rules! neg_impl {
             fn neg(self) -> $t { -self }
         }
 
-        forward_ref_unop! { impl Neg, neg for $t }
+        forward_ref_unop! { impl Neg, neg for $t,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )*)
 }
 
@@ -746,12 +765,14 @@ neg_impl! { isize i8 i16 i32 i64 i128 f16 f32 f64 f128 }
 /// ```
 #[lang = "add_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[diagnostic::on_unimplemented(
     message = "cannot add-assign `{Rhs}` to `{Self}`",
     label = "no implementation for `{Self} += {Rhs}`"
 )]
 #[doc(alias = "+")]
 #[doc(alias = "+=")]
+#[const_trait]
 pub trait AddAssign<Rhs = Self> {
     /// Performs the `+=` operation.
     ///
@@ -769,14 +790,17 @@ pub trait AddAssign<Rhs = Self> {
 macro_rules! add_assign_impl {
     ($($t:ty)+) => ($(
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl AddAssign for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const AddAssign for $t {
             #[inline]
             #[track_caller]
             #[rustc_inherit_overflow_checks]
             fn add_assign(&mut self, other: $t) { *self += other }
         }
 
-        forward_ref_op_assign! { impl AddAssign, add_assign for $t, $t }
+        forward_ref_op_assign! { impl AddAssign, add_assign for $t, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )+)
 }
 
@@ -813,12 +837,14 @@ add_assign_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f16 f32 f
 /// ```
 #[lang = "sub_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[diagnostic::on_unimplemented(
     message = "cannot subtract-assign `{Rhs}` from `{Self}`",
     label = "no implementation for `{Self} -= {Rhs}`"
 )]
 #[doc(alias = "-")]
 #[doc(alias = "-=")]
+#[const_trait]
 pub trait SubAssign<Rhs = Self> {
     /// Performs the `-=` operation.
     ///
@@ -836,14 +862,17 @@ pub trait SubAssign<Rhs = Self> {
 macro_rules! sub_assign_impl {
     ($($t:ty)+) => ($(
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl SubAssign for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const SubAssign for $t {
             #[inline]
             #[track_caller]
             #[rustc_inherit_overflow_checks]
             fn sub_assign(&mut self, other: $t) { *self -= other }
         }
 
-        forward_ref_op_assign! { impl SubAssign, sub_assign for $t, $t }
+        forward_ref_op_assign! { impl SubAssign, sub_assign for $t, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )+)
 }
 
@@ -871,12 +900,14 @@ sub_assign_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f16 f32 f
 /// ```
 #[lang = "mul_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[diagnostic::on_unimplemented(
     message = "cannot multiply-assign `{Self}` by `{Rhs}`",
     label = "no implementation for `{Self} *= {Rhs}`"
 )]
 #[doc(alias = "*")]
 #[doc(alias = "*=")]
+#[const_trait]
 pub trait MulAssign<Rhs = Self> {
     /// Performs the `*=` operation.
     ///
@@ -894,14 +925,17 @@ pub trait MulAssign<Rhs = Self> {
 macro_rules! mul_assign_impl {
     ($($t:ty)+) => ($(
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl MulAssign for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const MulAssign for $t {
             #[inline]
             #[track_caller]
             #[rustc_inherit_overflow_checks]
             fn mul_assign(&mut self, other: $t) { *self *= other }
         }
 
-        forward_ref_op_assign! { impl MulAssign, mul_assign for $t, $t }
+        forward_ref_op_assign! { impl MulAssign, mul_assign for $t, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )+)
 }
 
@@ -929,12 +963,14 @@ mul_assign_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f16 f32 f
 /// ```
 #[lang = "div_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[diagnostic::on_unimplemented(
     message = "cannot divide-assign `{Self}` by `{Rhs}`",
     label = "no implementation for `{Self} /= {Rhs}`"
 )]
 #[doc(alias = "/")]
 #[doc(alias = "/=")]
+#[const_trait]
 pub trait DivAssign<Rhs = Self> {
     /// Performs the `/=` operation.
     ///
@@ -952,13 +988,16 @@ pub trait DivAssign<Rhs = Self> {
 macro_rules! div_assign_impl {
     ($($t:ty)+) => ($(
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl DivAssign for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const DivAssign for $t {
             #[inline]
             #[track_caller]
             fn div_assign(&mut self, other: $t) { *self /= other }
         }
 
-        forward_ref_op_assign! { impl DivAssign, div_assign for $t, $t }
+        forward_ref_op_assign! { impl DivAssign, div_assign for $t, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )+)
 }
 
@@ -990,12 +1029,14 @@ div_assign_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f16 f32 f
 /// ```
 #[lang = "rem_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[diagnostic::on_unimplemented(
     message = "cannot calculate and assign the remainder of `{Self}` divided by `{Rhs}`",
     label = "no implementation for `{Self} %= {Rhs}`"
 )]
 #[doc(alias = "%")]
 #[doc(alias = "%=")]
+#[const_trait]
 pub trait RemAssign<Rhs = Self> {
     /// Performs the `%=` operation.
     ///
@@ -1013,13 +1054,16 @@ pub trait RemAssign<Rhs = Self> {
 macro_rules! rem_assign_impl {
     ($($t:ty)+) => ($(
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl RemAssign for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const RemAssign for $t {
             #[inline]
             #[track_caller]
             fn rem_assign(&mut self, other: $t) { *self %= other }
         }
 
-        forward_ref_op_assign! { impl RemAssign, rem_assign for $t, $t }
+        forward_ref_op_assign! { impl RemAssign, rem_assign for $t, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )+)
 }
 
diff --git a/core/src/ops/bit.rs b/core/src/ops/bit.rs
index deb54c8ba348e..001967282190f 100644
--- a/core/src/ops/bit.rs
+++ b/core/src/ops/bit.rs
@@ -30,7 +30,9 @@
 /// ```
 #[lang = "not"]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[doc(alias = "!")]
+#[const_trait]
 pub trait Not {
     /// The resulting type after applying the `!` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -54,21 +56,25 @@ pub trait Not {
 macro_rules! not_impl {
     ($($t:ty)*) => ($(
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl Not for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Not for $t {
             type Output = $t;
 
             #[inline]
             fn not(self) -> $t { !self }
         }
 
-        forward_ref_unop! { impl Not, not for $t }
+        forward_ref_unop! { impl Not, not for $t,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )*)
 }
 
 not_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 
 #[stable(feature = "not_never", since = "1.60.0")]
-impl Not for ! {
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl const Not for ! {
     type Output = !;
 
     #[inline]
@@ -137,10 +143,12 @@ impl Not for ! {
 #[lang = "bitand"]
 #[doc(alias = "&")]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[diagnostic::on_unimplemented(
     message = "no implementation for `{Self} & {Rhs}`",
     label = "no implementation for `{Self} & {Rhs}`"
 )]
+#[const_trait]
 pub trait BitAnd<Rhs = Self> {
     /// The resulting type after applying the `&` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -164,14 +172,17 @@ pub trait BitAnd<Rhs = Self> {
 macro_rules! bitand_impl {
     ($($t:ty)*) => ($(
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl BitAnd for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitAnd for $t {
             type Output = $t;
 
             #[inline]
             fn bitand(self, rhs: $t) -> $t { self & rhs }
         }
 
-        forward_ref_binop! { impl BitAnd, bitand for $t, $t }
+        forward_ref_binop! { impl BitAnd, bitand for $t, $t,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )*)
 }
 
@@ -237,10 +248,12 @@ bitand_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 #[lang = "bitor"]
 #[doc(alias = "|")]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[diagnostic::on_unimplemented(
     message = "no implementation for `{Self} | {Rhs}`",
     label = "no implementation for `{Self} | {Rhs}`"
 )]
+#[const_trait]
 pub trait BitOr<Rhs = Self> {
     /// The resulting type after applying the `|` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -264,14 +277,17 @@ pub trait BitOr<Rhs = Self> {
 macro_rules! bitor_impl {
     ($($t:ty)*) => ($(
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl BitOr for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitOr for $t {
             type Output = $t;
 
             #[inline]
             fn bitor(self, rhs: $t) -> $t { self | rhs }
         }
 
-        forward_ref_binop! { impl BitOr, bitor for $t, $t }
+        forward_ref_binop! { impl BitOr, bitor for $t, $t,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )*)
 }
 
@@ -337,10 +353,12 @@ bitor_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 #[lang = "bitxor"]
 #[doc(alias = "^")]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[diagnostic::on_unimplemented(
     message = "no implementation for `{Self} ^ {Rhs}`",
     label = "no implementation for `{Self} ^ {Rhs}`"
 )]
+#[const_trait]
 pub trait BitXor<Rhs = Self> {
     /// The resulting type after applying the `^` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -364,14 +382,17 @@ pub trait BitXor<Rhs = Self> {
 macro_rules! bitxor_impl {
     ($($t:ty)*) => ($(
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl BitXor for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitXor for $t {
             type Output = $t;
 
             #[inline]
             fn bitxor(self, other: $t) -> $t { self ^ other }
         }
 
-        forward_ref_binop! { impl BitXor, bitxor for $t, $t }
+        forward_ref_binop! { impl BitXor, bitxor for $t, $t,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )*)
 }
 
@@ -436,10 +457,12 @@ bitxor_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 #[lang = "shl"]
 #[doc(alias = "<<")]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[diagnostic::on_unimplemented(
     message = "no implementation for `{Self} << {Rhs}`",
     label = "no implementation for `{Self} << {Rhs}`"
 )]
+#[const_trait]
 pub trait Shl<Rhs = Self> {
     /// The resulting type after applying the `<<` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -461,7 +484,8 @@ pub trait Shl<Rhs = Self> {
 macro_rules! shl_impl {
     ($t:ty, $f:ty) => {
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl Shl<$f> for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Shl<$f> for $t {
             type Output = $t;
 
             #[inline]
@@ -471,7 +495,9 @@ macro_rules! shl_impl {
             }
         }
 
-        forward_ref_binop! { impl Shl, shl for $t, $f }
+        forward_ref_binop! { impl Shl, shl for $t, $f,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     };
 }
 
@@ -554,10 +580,12 @@ shl_impl_all! { u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize }
 #[lang = "shr"]
 #[doc(alias = ">>")]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[diagnostic::on_unimplemented(
     message = "no implementation for `{Self} >> {Rhs}`",
     label = "no implementation for `{Self} >> {Rhs}`"
 )]
+#[const_trait]
 pub trait Shr<Rhs = Self> {
     /// The resulting type after applying the `>>` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -579,7 +607,8 @@ pub trait Shr<Rhs = Self> {
 macro_rules! shr_impl {
     ($t:ty, $f:ty) => {
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl Shr<$f> for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const Shr<$f> for $t {
             type Output = $t;
 
             #[inline]
@@ -589,7 +618,9 @@ macro_rules! shr_impl {
             }
         }
 
-        forward_ref_binop! { impl Shr, shr for $t, $f }
+        forward_ref_binop! { impl Shr, shr for $t, $f,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     };
 }
 
@@ -681,10 +712,12 @@ shr_impl_all! { u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize }
 #[lang = "bitand_assign"]
 #[doc(alias = "&=")]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[diagnostic::on_unimplemented(
     message = "no implementation for `{Self} &= {Rhs}`",
     label = "no implementation for `{Self} &= {Rhs}`"
 )]
+#[const_trait]
 pub trait BitAndAssign<Rhs = Self> {
     /// Performs the `&=` operation.
     ///
@@ -714,12 +747,15 @@ pub trait BitAndAssign<Rhs = Self> {
 macro_rules! bitand_assign_impl {
     ($($t:ty)+) => ($(
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl BitAndAssign for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitAndAssign for $t {
             #[inline]
             fn bitand_assign(&mut self, other: $t) { *self &= other }
         }
 
-        forward_ref_op_assign! { impl BitAndAssign, bitand_assign for $t, $t }
+        forward_ref_op_assign! { impl BitAndAssign, bitand_assign for $t, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )+)
 }
 
@@ -752,10 +788,12 @@ bitand_assign_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 #[lang = "bitor_assign"]
 #[doc(alias = "|=")]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[diagnostic::on_unimplemented(
     message = "no implementation for `{Self} |= {Rhs}`",
     label = "no implementation for `{Self} |= {Rhs}`"
 )]
+#[const_trait]
 pub trait BitOrAssign<Rhs = Self> {
     /// Performs the `|=` operation.
     ///
@@ -785,12 +823,15 @@ pub trait BitOrAssign<Rhs = Self> {
 macro_rules! bitor_assign_impl {
     ($($t:ty)+) => ($(
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl BitOrAssign for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitOrAssign for $t {
             #[inline]
             fn bitor_assign(&mut self, other: $t) { *self |= other }
         }
 
-        forward_ref_op_assign! { impl BitOrAssign, bitor_assign for $t, $t }
+        forward_ref_op_assign! { impl BitOrAssign, bitor_assign for $t, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )+)
 }
 
@@ -823,10 +864,12 @@ bitor_assign_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 #[lang = "bitxor_assign"]
 #[doc(alias = "^=")]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[diagnostic::on_unimplemented(
     message = "no implementation for `{Self} ^= {Rhs}`",
     label = "no implementation for `{Self} ^= {Rhs}`"
 )]
+#[const_trait]
 pub trait BitXorAssign<Rhs = Self> {
     /// Performs the `^=` operation.
     ///
@@ -856,12 +899,15 @@ pub trait BitXorAssign<Rhs = Self> {
 macro_rules! bitxor_assign_impl {
     ($($t:ty)+) => ($(
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl BitXorAssign for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const BitXorAssign for $t {
             #[inline]
             fn bitxor_assign(&mut self, other: $t) { *self ^= other }
         }
 
-        forward_ref_op_assign! { impl BitXorAssign, bitxor_assign for $t, $t }
+        forward_ref_op_assign! { impl BitXorAssign, bitxor_assign for $t, $t,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     )+)
 }
 
@@ -892,10 +938,12 @@ bitxor_assign_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 #[lang = "shl_assign"]
 #[doc(alias = "<<=")]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[diagnostic::on_unimplemented(
     message = "no implementation for `{Self} <<= {Rhs}`",
     label = "no implementation for `{Self} <<= {Rhs}`"
 )]
+#[const_trait]
 pub trait ShlAssign<Rhs = Self> {
     /// Performs the `<<=` operation.
     ///
@@ -917,7 +965,8 @@ pub trait ShlAssign<Rhs = Self> {
 macro_rules! shl_assign_impl {
     ($t:ty, $f:ty) => {
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl ShlAssign<$f> for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const ShlAssign<$f> for $t {
             #[inline]
             #[rustc_inherit_overflow_checks]
             fn shl_assign(&mut self, other: $f) {
@@ -925,7 +974,9 @@ macro_rules! shl_assign_impl {
             }
         }
 
-        forward_ref_op_assign! { impl ShlAssign, shl_assign for $t, $f }
+        forward_ref_op_assign! { impl ShlAssign, shl_assign for $t, $f,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     };
 }
 
@@ -974,10 +1025,12 @@ shl_assign_impl_all! { u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize }
 #[lang = "shr_assign"]
 #[doc(alias = ">>=")]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
 #[diagnostic::on_unimplemented(
     message = "no implementation for `{Self} >>= {Rhs}`",
     label = "no implementation for `{Self} >>= {Rhs}`"
 )]
+#[const_trait]
 pub trait ShrAssign<Rhs = Self> {
     /// Performs the `>>=` operation.
     ///
@@ -999,7 +1052,8 @@ pub trait ShrAssign<Rhs = Self> {
 macro_rules! shr_assign_impl {
     ($t:ty, $f:ty) => {
         #[stable(feature = "op_assign_traits", since = "1.8.0")]
-        impl ShrAssign<$f> for $t {
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+        impl const ShrAssign<$f> for $t {
             #[inline]
             #[rustc_inherit_overflow_checks]
             fn shr_assign(&mut self, other: $f) {
@@ -1007,7 +1061,9 @@ macro_rules! shr_assign_impl {
             }
         }
 
-        forward_ref_op_assign! { impl ShrAssign, shr_assign for $t, $f }
+        forward_ref_op_assign! { impl ShrAssign, shr_assign for $t, $f,
+        #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]
+        #[rustc_const_unstable(feature = "const_ops", issue = "143802")] }
     };
 }
 
diff --git a/core/src/ops/range.rs b/core/src/ops/range.rs
index f33a33e6b752f..95d1e2069ac94 100644
--- a/core/src/ops/range.rs
+++ b/core/src/ops/range.rs
@@ -853,7 +853,7 @@ pub trait RangeBounds<T: ?Sized> {
     /// assert!( RangeBounds::is_empty(&(f32::NAN..5.0)));
     /// ```
     ///
-    /// But never empty is either side is unbounded:
+    /// But never empty if either side is unbounded:
     ///
     /// ```
     /// #![feature(range_bounds_is_empty)]
diff --git a/core/src/time.rs b/core/src/time.rs
index 0fb5c0bac7562..0cc570f4b7335 100644
--- a/core/src/time.rs
+++ b/core/src/time.rs
@@ -373,7 +373,6 @@ impl Duration {
     /// # Examples
     ///
     /// ```
-    /// #![feature(duration_constructors_lite)]
     /// use std::time::Duration;
     ///
     /// let duration = Duration::from_hours(6);
@@ -381,7 +380,8 @@ impl Duration {
     /// assert_eq!(6 * 60 * 60, duration.as_secs());
     /// assert_eq!(0, duration.subsec_nanos());
     /// ```
-    #[unstable(feature = "duration_constructors_lite", issue = "140881")]
+    #[stable(feature = "duration_constructors_lite", since = "CURRENT_RUSTC_VERSION")]
+    #[rustc_const_stable(feature = "duration_constructors_lite", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     #[inline]
     pub const fn from_hours(hours: u64) -> Duration {
@@ -401,7 +401,6 @@ impl Duration {
     /// # Examples
     ///
     /// ```
-    /// #![feature(duration_constructors_lite)]
     /// use std::time::Duration;
     ///
     /// let duration = Duration::from_mins(10);
@@ -409,7 +408,8 @@ impl Duration {
     /// assert_eq!(10 * 60, duration.as_secs());
     /// assert_eq!(0, duration.subsec_nanos());
     /// ```
-    #[unstable(feature = "duration_constructors_lite", issue = "140881")]
+    #[stable(feature = "duration_constructors_lite", since = "CURRENT_RUSTC_VERSION")]
+    #[rustc_const_stable(feature = "duration_constructors_lite", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     #[inline]
     pub const fn from_mins(mins: u64) -> Duration {
@@ -1100,7 +1100,8 @@ impl Duration {
 }
 
 #[stable(feature = "duration", since = "1.3.0")]
-impl Add for Duration {
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl const Add for Duration {
     type Output = Duration;
 
     #[inline]
@@ -1110,7 +1111,8 @@ impl Add for Duration {
 }
 
 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
-impl AddAssign for Duration {
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl const AddAssign for Duration {
     #[inline]
     fn add_assign(&mut self, rhs: Duration) {
         *self = *self + rhs;
@@ -1118,7 +1120,8 @@ impl AddAssign for Duration {
 }
 
 #[stable(feature = "duration", since = "1.3.0")]
-impl Sub for Duration {
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl const Sub for Duration {
     type Output = Duration;
 
     #[inline]
@@ -1128,7 +1131,8 @@ impl Sub for Duration {
 }
 
 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
-impl SubAssign for Duration {
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl const SubAssign for Duration {
     #[inline]
     fn sub_assign(&mut self, rhs: Duration) {
         *self = *self - rhs;
@@ -1136,7 +1140,8 @@ impl SubAssign for Duration {
 }
 
 #[stable(feature = "duration", since = "1.3.0")]
-impl Mul<u32> for Duration {
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl const Mul<u32> for Duration {
     type Output = Duration;
 
     #[inline]
@@ -1146,7 +1151,8 @@ impl Mul<u32> for Duration {
 }
 
 #[stable(feature = "symmetric_u32_duration_mul", since = "1.31.0")]
-impl Mul<Duration> for u32 {
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl const Mul<Duration> for u32 {
     type Output = Duration;
 
     #[inline]
@@ -1156,7 +1162,8 @@ impl Mul<Duration> for u32 {
 }
 
 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
-impl MulAssign<u32> for Duration {
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl const MulAssign<u32> for Duration {
     #[inline]
     fn mul_assign(&mut self, rhs: u32) {
         *self = *self * rhs;
@@ -1164,7 +1171,8 @@ impl MulAssign<u32> for Duration {
 }
 
 #[stable(feature = "duration", since = "1.3.0")]
-impl Div<u32> for Duration {
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl const Div<u32> for Duration {
     type Output = Duration;
 
     #[inline]
@@ -1175,7 +1183,8 @@ impl Div<u32> for Duration {
 }
 
 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
-impl DivAssign<u32> for Duration {
+#[rustc_const_unstable(feature = "const_ops", issue = "143802")]
+impl const DivAssign<u32> for Duration {
     #[inline]
     #[track_caller]
     fn div_assign(&mut self, rhs: u32) {
diff --git a/coretests/tests/lib.rs b/coretests/tests/lib.rs
index 75679bbac91fc..0c4d49f3c994b 100644
--- a/coretests/tests/lib.rs
+++ b/coretests/tests/lib.rs
@@ -36,7 +36,6 @@
 #![feature(drop_guard)]
 #![feature(duration_constants)]
 #![feature(duration_constructors)]
-#![feature(duration_constructors_lite)]
 #![feature(error_generic_member_access)]
 #![feature(exact_div)]
 #![feature(exact_size_is_empty)]
diff --git a/coretests/tests/tuple.rs b/coretests/tests/tuple.rs
index ea1e281425c89..5d680d1047237 100644
--- a/coretests/tests/tuple.rs
+++ b/coretests/tests/tuple.rs
@@ -37,7 +37,7 @@ fn test_partial_ord() {
     assert!(!((1.0f64, 2.0f64) <= (f64::NAN, 3.0)));
     assert!(!((1.0f64, 2.0f64) > (f64::NAN, 3.0)));
     assert!(!((1.0f64, 2.0f64) >= (f64::NAN, 3.0)));
-    assert!(((1.0f64, 2.0f64) < (2.0, f64::NAN)));
+    assert!((1.0f64, 2.0f64) < (2.0, f64::NAN));
     assert!(!((2.0f64, 2.0f64) < (2.0, f64::NAN)));
 }
 
diff --git a/std/src/collections/hash/map.rs b/std/src/collections/hash/map.rs
index edbdd0411457f..15a7a770d1a87 100644
--- a/std/src/collections/hash/map.rs
+++ b/std/src/collections/hash/map.rs
@@ -135,6 +135,8 @@ use crate::ops::Index;
 /// ]);
 /// ```
 ///
+/// ## `Entry` API
+///
 /// `HashMap` implements an [`Entry` API](#method.entry), which allows
 /// for complex methods of getting, setting, updating and removing keys and
 /// their values:
@@ -167,6 +169,8 @@ use crate::ops::Index;
 /// player_stats.entry("mana").and_modify(|mana| *mana += 200).or_insert(100);
 /// ```
 ///
+/// ## Usage with custom key types
+///
 /// The easiest way to use `HashMap` with a custom key type is to derive [`Eq`] and [`Hash`].
 /// We must also derive [`PartialEq`].
 ///
diff --git a/std/src/sys/fs/windows.rs b/std/src/sys/fs/windows.rs
index 9b674a251652b..09feddd0be9a1 100644
--- a/std/src/sys/fs/windows.rs
+++ b/std/src/sys/fs/windows.rs
@@ -80,7 +80,7 @@ pub struct OpenOptions {
     attributes: u32,
     share_mode: u32,
     security_qos_flags: u32,
-    security_attributes: *mut c::SECURITY_ATTRIBUTES,
+    inherit_handle: bool,
 }
 
 #[derive(Clone, PartialEq, Eq, Debug)]
@@ -203,7 +203,7 @@ impl OpenOptions {
             share_mode: c::FILE_SHARE_READ | c::FILE_SHARE_WRITE | c::FILE_SHARE_DELETE,
             attributes: 0,
             security_qos_flags: 0,
-            security_attributes: ptr::null_mut(),
+            inherit_handle: false,
         }
     }
 
@@ -243,8 +243,8 @@ impl OpenOptions {
         // receive is `SECURITY_ANONYMOUS = 0x0`, which we can't check for later on.
         self.security_qos_flags = flags | c::SECURITY_SQOS_PRESENT;
     }
-    pub fn security_attributes(&mut self, attrs: *mut c::SECURITY_ATTRIBUTES) {
-        self.security_attributes = attrs;
+    pub fn inherit_handle(&mut self, inherit: bool) {
+        self.inherit_handle = inherit;
     }
 
     fn get_access_mode(&self) -> io::Result<u32> {
@@ -307,12 +307,17 @@ impl File {
 
     fn open_native(path: &WCStr, opts: &OpenOptions) -> io::Result<File> {
         let creation = opts.get_creation_mode()?;
+        let sa = c::SECURITY_ATTRIBUTES {
+            nLength: size_of::<c::SECURITY_ATTRIBUTES>() as u32,
+            lpSecurityDescriptor: ptr::null_mut(),
+            bInheritHandle: opts.inherit_handle as c::BOOL,
+        };
         let handle = unsafe {
             c::CreateFileW(
                 path.as_ptr(),
                 opts.get_access_mode()?,
                 opts.share_mode,
-                opts.security_attributes,
+                if opts.inherit_handle { &sa } else { ptr::null() },
                 creation,
                 opts.get_flags_and_attributes(),
                 ptr::null_mut(),
diff --git a/std/src/sys/io/io_slice/uefi.rs b/std/src/sys/io/io_slice/uefi.rs
new file mode 100644
index 0000000000000..909cfbea0b7ba
--- /dev/null
+++ b/std/src/sys/io/io_slice/uefi.rs
@@ -0,0 +1,74 @@
+//! A buffer type used with `Write::write_vectored` for UEFI Networking APIs. Vectored writing to
+//! File is not supported as of UEFI Spec 2.11.
+
+use crate::marker::PhantomData;
+use crate::slice;
+
+#[derive(Copy, Clone)]
+#[repr(C)]
+pub struct IoSlice<'a> {
+    len: u32,
+    data: *const u8,
+    _p: PhantomData<&'a [u8]>,
+}
+
+impl<'a> IoSlice<'a> {
+    #[inline]
+    pub fn new(buf: &'a [u8]) -> IoSlice<'a> {
+        let len = buf.len().try_into().unwrap();
+        Self { len, data: buf.as_ptr(), _p: PhantomData }
+    }
+
+    #[inline]
+    pub fn advance(&mut self, n: usize) {
+        self.len = u32::try_from(n)
+            .ok()
+            .and_then(|n| self.len.checked_sub(n))
+            .expect("advancing IoSlice beyond its length");
+        unsafe { self.data = self.data.add(n) };
+    }
+
+    #[inline]
+    pub const fn as_slice(&self) -> &'a [u8] {
+        unsafe { slice::from_raw_parts(self.data, self.len as usize) }
+    }
+}
+
+#[repr(C)]
+pub struct IoSliceMut<'a> {
+    len: u32,
+    data: *mut u8,
+    _p: PhantomData<&'a mut [u8]>,
+}
+
+impl<'a> IoSliceMut<'a> {
+    #[inline]
+    pub fn new(buf: &'a mut [u8]) -> IoSliceMut<'a> {
+        let len = buf.len().try_into().unwrap();
+        Self { len, data: buf.as_mut_ptr(), _p: PhantomData }
+    }
+
+    #[inline]
+    pub fn advance(&mut self, n: usize) {
+        self.len = u32::try_from(n)
+            .ok()
+            .and_then(|n| self.len.checked_sub(n))
+            .expect("advancing IoSlice beyond its length");
+        unsafe { self.data = self.data.add(n) };
+    }
+
+    #[inline]
+    pub fn as_slice(&self) -> &[u8] {
+        unsafe { slice::from_raw_parts(self.data, self.len as usize) }
+    }
+
+    #[inline]
+    pub const fn into_slice(self) -> &'a mut [u8] {
+        unsafe { slice::from_raw_parts_mut(self.data, self.len as usize) }
+    }
+
+    #[inline]
+    pub fn as_mut_slice(&mut self) -> &mut [u8] {
+        unsafe { slice::from_raw_parts_mut(self.data, self.len as usize) }
+    }
+}
diff --git a/std/src/sys/io/mod.rs b/std/src/sys/io/mod.rs
index 4d0365d42fd9b..ae75f4d97b431 100644
--- a/std/src/sys/io/mod.rs
+++ b/std/src/sys/io/mod.rs
@@ -11,6 +11,9 @@ mod io_slice {
         } else if #[cfg(target_os = "wasi")] {
             mod wasi;
             pub use wasi::*;
+        } else if #[cfg(target_os = "uefi")] {
+            mod uefi;
+            pub use uefi::*;
         } else {
             mod unsupported;
             pub use unsupported::*;
diff --git a/std/src/sys/pal/uefi/tests.rs b/std/src/sys/pal/uefi/tests.rs
index 38658cc4e9ac4..56ca999cc7e99 100644
--- a/std/src/sys/pal/uefi/tests.rs
+++ b/std/src/sys/pal/uefi/tests.rs
@@ -1,7 +1,13 @@
+//! These tests are not run automatically right now. Please run these tests manually by copying them
+//! to a separate project when modifying any related code.
+
 use super::alloc::*;
-use super::time::*;
+use super::time::system_time_internal::{from_uefi, to_uefi};
+use crate::io::{IoSlice, IoSliceMut};
 use crate::time::Duration;
 
+const SECS_IN_MINUTE: u64 = 60;
+
 #[test]
 fn align() {
     // UEFI ABI specifies that allocation alignment minimum is always 8. So this can be
@@ -23,19 +29,177 @@ fn align() {
 }
 
 #[test]
-fn epoch() {
-    let t = r_efi::system::Time {
-        year: 1970,
+fn systemtime_start() {
+    let t = r_efi::efi::Time {
+        year: 1900,
         month: 1,
         day: 1,
         hour: 0,
         minute: 0,
         second: 0,
         nanosecond: 0,
-        timezone: r_efi::efi::UNSPECIFIED_TIMEZONE,
+        timezone: -1440,
         daylight: 0,
+        pad2: 0,
+    };
+    assert_eq!(from_uefi(&t), Duration::new(0, 0));
+    assert_eq!(t, to_uefi(&from_uefi(&t), -1440, 0).unwrap());
+    assert!(to_uefi(&from_uefi(&t), 0, 0).is_none());
+}
+
+#[test]
+fn systemtime_utc_start() {
+    let t = r_efi::efi::Time {
+        year: 1900,
+        month: 1,
+        day: 1,
+        hour: 0,
+        minute: 0,
+        second: 0,
         pad1: 0,
+        nanosecond: 0,
+        timezone: 0,
+        daylight: 0,
         pad2: 0,
     };
-    assert_eq!(system_time_internal::uefi_time_to_duration(t), Duration::new(0, 0));
+    assert_eq!(from_uefi(&t), Duration::new(1440 * SECS_IN_MINUTE, 0));
+    assert_eq!(t, to_uefi(&from_uefi(&t), 0, 0).unwrap());
+    assert!(to_uefi(&from_uefi(&t), -1440, 0).is_some());
+}
+
+#[test]
+fn systemtime_end() {
+    let t = r_efi::efi::Time {
+        year: 9999,
+        month: 12,
+        day: 31,
+        hour: 23,
+        minute: 59,
+        second: 59,
+        pad1: 0,
+        nanosecond: 0,
+        timezone: 1440,
+        daylight: 0,
+        pad2: 0,
+    };
+    assert!(to_uefi(&from_uefi(&t), 1440, 0).is_some());
+    assert!(to_uefi(&from_uefi(&t), 1439, 0).is_none());
+}
+
+// UEFI IoSlice and IoSliceMut Tests
+//
+// Strictly speaking, vectored read/write types for UDP4, UDP6, TCP4, TCP6 are defined
+// separately in the UEFI Spec. However, they have the same signature. These tests just ensure
+// that `IoSlice` and `IoSliceMut` are compatible with the vectored types for all the
+// networking protocols.
+
+unsafe fn to_slice<T>(val: &T) -> &[u8] {
+    let len = size_of_val(val);
+    unsafe { crate::slice::from_raw_parts(crate::ptr::from_ref(val).cast(), len) }
+}
+
+#[test]
+fn io_slice_single() {
+    let mut data = [0, 1, 2, 3, 4];
+
+    let tcp4_frag = r_efi::protocols::tcp4::FragmentData {
+        fragment_length: data.len().try_into().unwrap(),
+        fragment_buffer: data.as_mut_ptr().cast(),
+    };
+    let tcp6_frag = r_efi::protocols::tcp6::FragmentData {
+        fragment_length: data.len().try_into().unwrap(),
+        fragment_buffer: data.as_mut_ptr().cast(),
+    };
+    let udp4_frag = r_efi::protocols::udp4::FragmentData {
+        fragment_length: data.len().try_into().unwrap(),
+        fragment_buffer: data.as_mut_ptr().cast(),
+    };
+    let udp6_frag = r_efi::protocols::udp6::FragmentData {
+        fragment_length: data.len().try_into().unwrap(),
+        fragment_buffer: data.as_mut_ptr().cast(),
+    };
+    let io_slice = IoSlice::new(&data);
+
+    unsafe {
+        assert_eq!(to_slice(&io_slice), to_slice(&tcp4_frag));
+        assert_eq!(to_slice(&io_slice), to_slice(&tcp6_frag));
+        assert_eq!(to_slice(&io_slice), to_slice(&udp4_frag));
+        assert_eq!(to_slice(&io_slice), to_slice(&udp6_frag));
+    }
+}
+
+#[test]
+fn io_slice_mut_single() {
+    let mut data = [0, 1, 2, 3, 4];
+
+    let tcp4_frag = r_efi::protocols::tcp4::FragmentData {
+        fragment_length: data.len().try_into().unwrap(),
+        fragment_buffer: data.as_mut_ptr().cast(),
+    };
+    let tcp6_frag = r_efi::protocols::tcp6::FragmentData {
+        fragment_length: data.len().try_into().unwrap(),
+        fragment_buffer: data.as_mut_ptr().cast(),
+    };
+    let udp4_frag = r_efi::protocols::udp4::FragmentData {
+        fragment_length: data.len().try_into().unwrap(),
+        fragment_buffer: data.as_mut_ptr().cast(),
+    };
+    let udp6_frag = r_efi::protocols::udp6::FragmentData {
+        fragment_length: data.len().try_into().unwrap(),
+        fragment_buffer: data.as_mut_ptr().cast(),
+    };
+    let io_slice_mut = IoSliceMut::new(&mut data);
+
+    unsafe {
+        assert_eq!(to_slice(&io_slice_mut), to_slice(&tcp4_frag));
+        assert_eq!(to_slice(&io_slice_mut), to_slice(&tcp6_frag));
+        assert_eq!(to_slice(&io_slice_mut), to_slice(&udp4_frag));
+        assert_eq!(to_slice(&io_slice_mut), to_slice(&udp6_frag));
+    }
+}
+
+#[test]
+fn io_slice_multi() {
+    let mut data = [0, 1, 2, 3, 4];
+
+    let tcp4_frag = r_efi::protocols::tcp4::FragmentData {
+        fragment_length: data.len().try_into().unwrap(),
+        fragment_buffer: data.as_mut_ptr().cast(),
+    };
+    let rhs =
+        [tcp4_frag.clone(), tcp4_frag.clone(), tcp4_frag.clone(), tcp4_frag.clone(), tcp4_frag];
+    let lhs = [
+        IoSlice::new(&data),
+        IoSlice::new(&data),
+        IoSlice::new(&data),
+        IoSlice::new(&data),
+        IoSlice::new(&data),
+    ];
+
+    unsafe {
+        assert_eq!(to_slice(&lhs), to_slice(&rhs));
+    }
+}
+
+#[test]
+fn io_slice_basic() {
+    let data = [0, 1, 2, 3, 4];
+    let mut io_slice = IoSlice::new(&data);
+
+    assert_eq!(data, io_slice.as_slice());
+    io_slice.advance(2);
+    assert_eq!(&data[2..], io_slice.as_slice());
+}
+
+#[test]
+fn io_slice_mut_basic() {
+    let data = [0, 1, 2, 3, 4];
+    let mut data_clone = [0, 1, 2, 3, 4];
+    let mut io_slice_mut = IoSliceMut::new(&mut data_clone);
+
+    assert_eq!(data, io_slice_mut.as_slice());
+    assert_eq!(data, io_slice_mut.as_mut_slice());
+
+    io_slice_mut.advance(2);
+    assert_eq!(&data[2..], io_slice_mut.into_slice());
 }
diff --git a/std/src/sys/pal/uefi/time.rs b/std/src/sys/pal/uefi/time.rs
index eeb2c35ffbbc9..a5ab76903274d 100644
--- a/std/src/sys/pal/uefi/time.rs
+++ b/std/src/sys/pal/uefi/time.rs
@@ -1,16 +1,42 @@
 use crate::time::Duration;
 
-const SECS_IN_MINUTE: u64 = 60;
-const SECS_IN_HOUR: u64 = SECS_IN_MINUTE * 60;
-const SECS_IN_DAY: u64 = SECS_IN_HOUR * 24;
-
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
 pub struct Instant(Duration);
 
+/// When a Timezone is specified, the stored Duration is in UTC. If timezone is unspecified, then
+/// the timezone is assumed to be in UTC.
+///
+/// UEFI SystemTime is stored as Duration from 1900-01-01-00:00:00 with timezone -1440 as anchor
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
 pub struct SystemTime(Duration);
 
-pub const UNIX_EPOCH: SystemTime = SystemTime(Duration::from_secs(0));
+pub const UNIX_EPOCH: SystemTime = SystemTime::from_uefi(r_efi::efi::Time {
+    year: 1970,
+    month: 1,
+    day: 1,
+    hour: 0,
+    minute: 0,
+    second: 0,
+    nanosecond: 0,
+    timezone: 0,
+    daylight: 0,
+    pad1: 0,
+    pad2: 0,
+});
+
+const MAX_UEFI_TIME: SystemTime = SystemTime::from_uefi(r_efi::efi::Time {
+    year: 9999,
+    month: 12,
+    day: 31,
+    hour: 23,
+    minute: 59,
+    second: 59,
+    nanosecond: 999_999_999,
+    timezone: 1440,
+    daylight: 0,
+    pad1: 0,
+    pad2: 0,
+});
 
 impl Instant {
     pub fn now() -> Instant {
@@ -40,6 +66,15 @@ impl Instant {
 }
 
 impl SystemTime {
+    pub(crate) const fn from_uefi(t: r_efi::efi::Time) -> Self {
+        Self(system_time_internal::from_uefi(&t))
+    }
+
+    #[expect(dead_code)]
+    pub(crate) const fn to_uefi(self, timezone: i16, daylight: u8) -> Option<r_efi::efi::Time> {
+        system_time_internal::to_uefi(&self.0, timezone, daylight)
+    }
+
     pub fn now() -> SystemTime {
         system_time_internal::now()
             .unwrap_or_else(|| panic!("time not implemented on this platform"))
@@ -50,11 +85,14 @@ impl SystemTime {
     }
 
     pub fn checked_add_duration(&self, other: &Duration) -> Option<SystemTime> {
-        Some(SystemTime(self.0.checked_add(*other)?))
+        let temp = Self(self.0.checked_add(*other)?);
+
+        // Check if can be represented in UEFI
+        if temp <= MAX_UEFI_TIME { Some(temp) } else { None }
     }
 
     pub fn checked_sub_duration(&self, other: &Duration) -> Option<SystemTime> {
-        Some(SystemTime(self.0.checked_sub(*other)?))
+        self.0.checked_sub(*other).map(Self)
     }
 }
 
@@ -66,51 +104,132 @@ pub(crate) mod system_time_internal {
     use crate::mem::MaybeUninit;
     use crate::ptr::NonNull;
 
+    const SECS_IN_MINUTE: u64 = 60;
+    const SECS_IN_HOUR: u64 = SECS_IN_MINUTE * 60;
+    const SECS_IN_DAY: u64 = SECS_IN_HOUR * 24;
+    const TIMEZONE_DELTA: u64 = 1440 * SECS_IN_MINUTE;
+
     pub fn now() -> Option<SystemTime> {
         let runtime_services: NonNull<RuntimeServices> = helpers::runtime_services()?;
         let mut t: MaybeUninit<Time> = MaybeUninit::uninit();
         let r = unsafe {
             ((*runtime_services.as_ptr()).get_time)(t.as_mut_ptr(), crate::ptr::null_mut())
         };
-
         if r.is_error() {
             return None;
         }
 
         let t = unsafe { t.assume_init() };
 
-        Some(SystemTime(uefi_time_to_duration(t)))
+        Some(SystemTime::from_uefi(t))
     }
 
-    // This algorithm is based on the one described in the post
-    // https://blog.reverberate.org/2020/05/12/optimizing-date-algorithms.html
-    pub(crate) const fn uefi_time_to_duration(t: r_efi::system::Time) -> Duration {
-        assert!(t.month <= 12);
-        assert!(t.month != 0);
+    /// This algorithm is a modified form of the one described in the post
+    /// https://blog.reverberate.org/2020/05/12/optimizing-date-algorithms.html
+    ///
+    /// The changes are to use 1900-01-01-00:00:00 with timezone -1440 as anchor instead of UNIX
+    /// epoch used in the original algorithm.
+    pub(crate) const fn from_uefi(t: &Time) -> Duration {
+        assert!(t.month <= 12 && t.month != 0);
+        assert!(t.year >= 1900 && t.year <= 9999);
+        assert!(t.day <= 31 && t.day != 0);
+
+        assert!(t.second < 60);
+        assert!(t.minute < 60);
+        assert!(t.hour < 24);
+        assert!(t.nanosecond < 1_000_000_000);
+
+        assert!(
+            (t.timezone <= 1440 && t.timezone >= -1440)
+                || t.timezone == r_efi::efi::UNSPECIFIED_TIMEZONE
+        );
 
         const YEAR_BASE: u32 = 4800; /* Before min year, multiple of 400. */
 
-        // Calculate the number of days since 1/1/1970
+        // Calculate the number of days since 1/1/1900. This is the earliest supported date in UEFI
+        // time.
         // Use 1 March as the start
         let (m_adj, overflow): (u32, bool) = (t.month as u32).overflowing_sub(3);
         let (carry, adjust): (u32, u32) = if overflow { (1, 12) } else { (0, 0) };
         let y_adj: u32 = (t.year as u32) + YEAR_BASE - carry;
         let month_days: u32 = (m_adj.wrapping_add(adjust) * 62719 + 769) / 2048;
         let leap_days: u32 = y_adj / 4 - y_adj / 100 + y_adj / 400;
-        let days: u32 = y_adj * 365 + leap_days + month_days + (t.day as u32 - 1) - 2472632;
+        let days: u32 = y_adj * 365 + leap_days + month_days + (t.day as u32 - 1) - 2447065;
 
         let localtime_epoch: u64 = (days as u64) * SECS_IN_DAY
             + (t.second as u64)
             + (t.minute as u64) * SECS_IN_MINUTE
             + (t.hour as u64) * SECS_IN_HOUR;
 
-        let utc_epoch: u64 = if t.timezone == r_efi::efi::UNSPECIFIED_TIMEZONE {
-            localtime_epoch
+        // Calculate the offset from 1/1/1900 at timezone -1440 min
+        let adjusted_localtime_epoc: u64 = localtime_epoch + TIMEZONE_DELTA;
+
+        let epoch: u64 = if t.timezone == r_efi::efi::UNSPECIFIED_TIMEZONE {
+            adjusted_localtime_epoc
         } else {
-            (localtime_epoch as i64 + (t.timezone as i64) * SECS_IN_MINUTE as i64) as u64
+            adjusted_localtime_epoc
+                .checked_add_signed((t.timezone as i64) * SECS_IN_MINUTE as i64)
+                .unwrap()
         };
 
-        Duration::new(utc_epoch, t.nanosecond)
+        Duration::new(epoch, t.nanosecond)
+    }
+
+    /// This algorithm is a modifed version of the one described in the post:
+    /// https://howardhinnant.github.io/date_algorithms.html#clive_from_days
+    ///
+    /// The changes are to use 1900-01-01-00:00:00 with timezone -1440 as anchor instead of UNIX
+    /// epoch used in the original algorithm.
+    pub(crate) const fn to_uefi(dur: &Duration, timezone: i16, daylight: u8) -> Option<Time> {
+        // Check timzone validity
+        assert!(timezone <= 1440 && timezone >= -1440);
+
+        // FIXME(#126043): use checked_sub_signed once stablized
+        let secs =
+            dur.as_secs().checked_add_signed((-timezone as i64) * SECS_IN_MINUTE as i64).unwrap();
+
+        // Convert to seconds since 1900-01-01-00:00:00 in timezone.
+        let Some(secs) = secs.checked_sub(TIMEZONE_DELTA) else { return None };
+
+        let days = secs / SECS_IN_DAY;
+        let remaining_secs = secs % SECS_IN_DAY;
+
+        let z = days + 693901;
+        let era = z / 146097;
+        let doe = z - (era * 146097);
+        let yoe = (doe - doe / 1460 + doe / 36524 - doe / 146096) / 365;
+        let mut y = yoe + era * 400;
+        let doy = doe - (365 * yoe + yoe / 4 - yoe / 100);
+        let mp = (5 * doy + 2) / 153;
+        let d = doy - (153 * mp + 2) / 5 + 1;
+        let m = if mp < 10 { mp + 3 } else { mp - 9 };
+
+        if m <= 2 {
+            y += 1;
+        }
+
+        let hour = (remaining_secs / SECS_IN_HOUR) as u8;
+        let minute = ((remaining_secs % SECS_IN_HOUR) / SECS_IN_MINUTE) as u8;
+        let second = (remaining_secs % SECS_IN_MINUTE) as u8;
+
+        // Check Bounds
+        if y >= 1900 && y <= 9999 {
+            Some(Time {
+                year: y as u16,
+                month: m as u8,
+                day: d as u8,
+                hour,
+                minute,
+                second,
+                nanosecond: dur.subsec_nanos(),
+                timezone,
+                daylight,
+                pad1: 0,
+                pad2: 0,
+            })
+        } else {
+            None
+        }
     }
 }
 
diff --git a/std/src/sys/process/windows.rs b/std/src/sys/process/windows.rs
index 1ee3fbd285f52..f9e15b824757d 100644
--- a/std/src/sys/process/windows.rs
+++ b/std/src/sys/process/windows.rs
@@ -623,16 +623,10 @@ impl Stdio {
             // permissions as well as the ability to be inherited to child
             // processes (as this is about to be inherited).
             Stdio::Null => {
-                let size = size_of::<c::SECURITY_ATTRIBUTES>();
-                let mut sa = c::SECURITY_ATTRIBUTES {
-                    nLength: size as u32,
-                    lpSecurityDescriptor: ptr::null_mut(),
-                    bInheritHandle: 1,
-                };
                 let mut opts = OpenOptions::new();
                 opts.read(stdio_id == c::STD_INPUT_HANDLE);
                 opts.write(stdio_id != c::STD_INPUT_HANDLE);
-                opts.security_attributes(&mut sa);
+                opts.inherit_handle(true);
                 File::open(Path::new(r"\\.\NUL"), &opts).map(|file| file.into_inner())
             }
         }
diff --git a/std/tests/env.rs b/std/tests/env.rs
index e754cf8263b0f..b53fd69b7070b 100644
--- a/std/tests/env.rs
+++ b/std/tests/env.rs
@@ -16,7 +16,7 @@ fn test_self_exe_path() {
 
 #[test]
 fn test() {
-    assert!((!Path::new("test-path").is_absolute()));
+    assert!(!Path::new("test-path").is_absolute());
 
     #[cfg(not(target_env = "sgx"))]
     current_dir().unwrap();