Rollup merge of rust-lang#73580 - RalfJung:deprecate-wrapping-offset-from, r=Amanieu

deprecate wrapping_offset_from

As per rust-lang#41079 (comment) which seems like a consensus.

r? @Amanieu

Author: Manishearth

src/libcore/ptr/const_ptr.rs

@@ -396,6 +396,12 @@ impl<T: ?Sized> *const T {
     /// assert_eq!(ptr2.wrapping_offset_from(ptr1), 2);
     /// ```
     #[unstable(feature = "ptr_wrapping_offset_from", issue = "41079")]
+    #[rustc_deprecated(
+        since = "1.46.0",
+        reason = "Pointer distances across allocation \
+        boundaries are not typically meaningful. \
+        Use integer subtraction if you really need this."
+    )]
     #[inline]
     pub fn wrapping_offset_from(self, origin: *const T) -> isize
     where

src/libcore/ptr/mut_ptr.rs

@@ -446,11 +446,18 @@ impl<T: ?Sized> *mut T {
     /// assert_eq!(ptr2.wrapping_offset_from(ptr1), 2);
     /// ```
     #[unstable(feature = "ptr_wrapping_offset_from", issue = "41079")]
+    #[rustc_deprecated(
+        since = "1.46.0",
+        reason = "Pointer distances across allocation \
+        boundaries are not typically meaningful. \
+        Use integer subtraction if you really need this."
+    )]
     #[inline]
     pub fn wrapping_offset_from(self, origin: *const T) -> isize
     where
         T: Sized,
     {
+        #[allow(deprecated_in_future, deprecated)]
         (self as *const T).wrapping_offset_from(origin)
     }