Update to nightly 2023-05-23

Minimal changes needed

Author: Techcable

libs/context/src/handle.rs

@@ -4,6 +4,7 @@
 use core::ptr::{self, NonNull, Pointee};
 use core::marker::PhantomData;
 use core::sync::atomic::{self, AtomicPtr, AtomicUsize, Ordering};
+use core::mem::ManuallyDrop;
 
 use alloc::boxed::Box;
 use alloc::vec::Vec;
@@ -323,8 +324,8 @@ impl<C: RawHandleImpl> GcHandleBucket<C> {
 /// depending on whether the value pointer is null.
 #[repr(C)]
 pub union HandleSlot<C: RawHandleImpl> {
-    freed: FreedHandleSlot<C>,
-    valid: GcRawHandle<C>
+    freed: ManuallyDrop<FreedHandleSlot<C>>,
+    valid: ManuallyDrop<GcRawHandle<C>>
 }
 impl<C: RawHandleImpl> HandleSlot<C> {
     /// Load the current value of this pointer
@@ -663,4 +664,4 @@ unsafe impl<C> HandleCollectorId for CollectorId<C>
             GcHandle::new(NonNull::from(raw), weak_collector, metadata)
         }
     }
-}
+}

libs/context/src/lib.rs

@@ -1,7 +1,5 @@
 #![feature(
     negative_impls, // !Send is much cleaner than `PhantomData<Rc>`
-    untagged_unions, // I want to avoid ManuallyDrop in unions
-    generic_associated_types, // Finally!
     ptr_metadata
 )]
 #![allow(

libs/context/src/state/sync.rs

@@ -232,7 +232,7 @@ unsafe impl<C> super::RawContext<C> for RawContext<C>
         let shadow_stack = &*self.shadow_stack.get();
         let ptr = self as *const RawContext<C> as *mut RawContext<C>;
         debug_assert!(state.known_contexts.get_mut().contains(&ptr));
-        let mut pending = state.pending.as_mut().unwrap();
+        let pending: &mut _ = state.pending.as_mut().unwrap();
         // Change our state to mark we are now waiting at a safepoint
         assert_eq!(self.state.replace(ContextState::SafePoint {
             collection_id: pending.id

libs/simple/src/lib.rs

@@ -25,16 +25,13 @@
     negative_impls, // impl !Send is much cleaner than PhantomData<Rc<()>>
     exhaustive_patterns, // Allow exhaustive matching against never
     const_alloc_layout, // Used for StaticType
-    untagged_unions, // Why isn't this stable?
     new_uninit, // Until Rust has const generics, this is how we init arrays..
     ptr_metadata, // Needed to abstract over Sized/unsized types
     // Used for const layout computation:
     const_mut_refs,
     const_align_of_val,
     // Needed for field_offset!
-    const_ptr_offset_from,
     const_refs_to_cell,
-    generic_associated_types
 )]
 #![feature(drain_filter)]
 #![allow(

src/epsilon.rs

@@ -17,8 +17,7 @@ use crate::{CollectorId, GcContext, GcSafe, GcSimpleAlloc, GcSystem, Trace};
 use std::ptr::NonNull;
 use std::alloc::Layout;
 use std::rc::Rc;
-use std::cell::Cell;
-use std::lazy::OnceCell;
+use std::cell::{Cell, OnceCell};
 
 use self::alloc::{EpsilonAlloc};
 use self::layout::EpsilonRawVec;

src/lib.rs

@@ -3,14 +3,11 @@
     coerce_unsized, // RFC 0982 - DST coercion
     unsize,
     trait_alias, // RFC 1733 - Trait aliases
-    generic_associated_types, // RFC 1598 - Generic associated types
     // Needed for epsilon collector:
-    once_cell, // RFC 2788 (Probably will be accepted)
     negative_impls, // More elegant than marker types
     alloc_layout_extra,
     const_mut_refs,
     const_option,
-    const_slice_from_raw_parts,
     const_transmute_copy,
     slice_range, // Convenient for bounds checking :)
 )]