NIGHTLY: const Deref and From; as_array_of_cells

Author: peter-lyons-kehl

rust-toolchain.toml

@@ -0,0 +1,2 @@
+[toolchain]
+channel = "nightly"

src/lib.rs

@@ -1,5 +1,6 @@
 #![doc = include_str!("../README.md")]
 #![cfg_attr(not(any(doc, test)), no_std)]
+#![feature(const_convert, const_trait_impl)]
 
 use core::any::Any;
 use core::cell::Cell;
@@ -58,20 +59,26 @@ impl<T: Any> NonDeDuplicated<T> {
     }
 }
 
-impl<T: Any> Deref for NonDeDuplicated<T> {
+impl<T: Any> const Deref for NonDeDuplicated<T> {
     type Target = T;
 
     fn deref(&self) -> &Self::Target {
         self.get()
     }
 }
 
-impl<T: Any> From<T> for NonDeDuplicated<T> {
+impl<T: Any> const From<T> for NonDeDuplicated<T> {
     fn from(value: T) -> Self {
         Self::new(value)
     }
 }
 
+impl<T: Any, const N: usize> NonDeDuplicated<[T; N]> {
+    pub const fn as_array_of_cells(&self) -> &[NonDeDuplicated<T>; N] {
+        unsafe { core::mem::transmute(self.cell.as_array_of_cells()) }
+    }
+}
+
 /// For now, [Sync] requires that `T` is both [Sync] AND [Send], following
 /// [std::sync::Mutex](https://doc.rust-lang.org/nightly/std/sync/struct.Mutex.html#impl-Sync-for-Mutex%3CT%3E).
 /// However, from <https://doc.rust-lang.org/nightly/core/marker/trait.Sync.html> it seems that `T: