From 48e0dfde0084908901b50fc8d5386c9669b8b4cf Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Fri, 23 Sep 2022 19:48:49 +0900
Subject: [PATCH] Use offset_of! instead of cfg-ed addr_of!

---
 crossbeam-epoch/build.rs      |  3 ---
 crossbeam-epoch/src/atomic.rs | 12 +++++++-----
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/crossbeam-epoch/build.rs b/crossbeam-epoch/build.rs
index 2a7563509..b3bd15a5a 100644
--- a/crossbeam-epoch/build.rs
+++ b/crossbeam-epoch/build.rs
@@ -48,9 +48,6 @@ fn main() {
         println!("cargo:rustc-cfg=crossbeam_no_atomic_cas");
     }
 
-    if !cfg.probe_rustc_version(1, 51) {
-        println!("cargo:rustc-cfg=crossbeam_no_raw_ref_macros");
-    }
     if !cfg.probe_rustc_version(1, 61) {
         println!("cargo:rustc-cfg=crossbeam_no_const_fn_trait_bound");
     }
diff --git a/crossbeam-epoch/src/atomic.rs b/crossbeam-epoch/src/atomic.rs
index fb913352e..7fbacc18d 100644
--- a/crossbeam-epoch/src/atomic.rs
+++ b/crossbeam-epoch/src/atomic.rs
@@ -14,7 +14,9 @@ use crate::guard::Guard;
 use crate::primitive::sync::atomic::AtomicPtr;
 #[cfg(not(miri))]
 use crate::primitive::sync::atomic::AtomicUsize;
+
 use crossbeam_utils::atomic::AtomicConsume;
+use memoffset::offset_of;
 
 /// The error returned on failed compare-and-swap operation.
 pub struct CompareExchangeError<'g, T: ?Sized + Pointable, P: Pointer<T>> {
@@ -208,12 +210,12 @@ impl<T> Pointable for [MaybeUninit<T>] {
 
     unsafe fn as_ptr(ptr: *mut ()) -> *const Self {
         let array = ptr.cast::<Array<T>>();
-        #[cfg(not(crossbeam_no_raw_ref_macros))]
-        let ptr = ptr::addr_of!((*array).elements) as *const _;
-        #[cfg(crossbeam_no_raw_ref_macros)]
-        let ptr = (*array).elements.as_ptr();
+        let elements = array
+            .cast::<u8>()
+            .add(offset_of!(Array<T>, elements))
+            .cast::<MaybeUninit<T>>();
         // TODO: use ptr::slice_from_raw_parts once we bump MSRV to 1.42
-        slice::from_raw_parts(ptr, (*array).len)
+        slice::from_raw_parts(elements, (*array).len)
     }
 
     unsafe fn as_mut_ptr(ptr: *mut ()) -> *mut Self {