Make it compile on stable

.github/workflows/ci.yml

@@ -152,17 +152,16 @@ jobs:
       - name: Test with Itanium backend
         run: LITHIUM_BACKEND=itanium cargo valgrind test
 
-  # TODO: Restore this when strict provenance APIs are in stable.
-  # test_stable:
-  #   runs-on: ubuntu-latest
-  #   if: success() || failure()
-  #   steps:
-  #     - name: Checkout
-  #       uses: actions/checkout@v4
-  #     - name: Install Rust
-  #       run: rustup update stable && rustup default stable
-  #     - name: Test with panic backend
-  #       run: cargo test
+  test_stable:
+    runs-on: ubuntu-latest
+    if: success() || failure()
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Install Rust
+        run: rustup update stable && rustup default stable
+      - name: Test with panic backend
+        run: cargo test
 
   lint:
     runs-on: ubuntu-latest

Cargo.toml

@@ -11,6 +11,7 @@ edition = "2021"
 links = "rustlithium"  # Force uniqueness of crate version
 
 [dependencies]
+sptr = "0.3.2"
 typeid = "1.0.2"
 
 [dev-dependencies]

src/heterogeneous_stack/array.rs

@@ -2,6 +2,12 @@ use super::align::assert_aligned;
 use core::cell::{Cell, UnsafeCell};
 use core::mem::MaybeUninit;
 
+#[allow(
+    unused_imports,
+    reason = "XXX: remove when strict provenance is stabilized"
+)]
+use sptr::Strict;
+
 /// A thread-unsafe array-backed stack allocator.
 ///
 /// This allocator can allocate values with sizes that are multiples of `align_of::<AlignAs>()`,
@@ -49,7 +55,9 @@ impl<AlignAs, const CAPACITY: usize> Stack<AlignAs, CAPACITY> {
         if n == 0 {
             // Dangling pointers to ZSTs are always valid and unique. Creating `*mut AlignAs`
             // instead of *mut u8` forces alignment.
-            return Some(core::ptr::dangling_mut::<AlignAs>().cast());
+            // XXX: Replace with `return Some(core::ptr::dangling_mut::<AlignAs>().cast());` when
+            // strict provenance is stabilized
+            return Some(align_of::<AlignAs>() as *mut u8);
         }
 
         // SAFETY: len <= CAPACITY is an invariant

src/heterogeneous_stack/heap.rs

@@ -3,6 +3,12 @@ use alloc::alloc;
 use core::alloc::Layout;
 use core::marker::PhantomData;
 
+#[allow(
+    unused_imports,
+    reason = "XXX: remove when strict provenance is stabilized"
+)]
+use sptr::Strict;
+
 /// A heap-backed allocator.
 ///
 /// This allocator can allocate values with sizes that are multiples of `align_of::<AlignAs>()`,

src/heterogeneous_stack/unbounded.rs

@@ -1,5 +1,11 @@
 use super::{align::assert_aligned, array::Stack as BoundedStack, heap::Heap};
 
+#[allow(
+    unused_imports,
+    reason = "XXX: remove when strict provenance is stabilized"
+)]
+use sptr::Strict;
+
 /// A thread-unsafe heterogeneous stack, using statically allocated space when possible.
 ///
 /// Although the stack doesn't track runtime types, all elements are considered independent. Stack

src/lib.rs

@@ -140,6 +140,10 @@
     clippy::inline_always,
     reason = "I'm not an idiot, this is a result of benchmarking/profiling"
 )]
+#![allow(
+    unstable_name_collisions,
+    reason = "XXX: remove when strict provenance is stabilized"
+)]
 
 extern crate alloc;