Stabilize mem::conjure_zst

library/core/src/mem/mod.rs

@@ -1692,16 +1692,16 @@ pub macro offset_of($Container:ty, $($fields:expr)+ $(,)?) {
 /// # Examples
 ///
 /// ```
-/// #![feature(mem_conjure_zst)]
 /// use std::mem::conjure_zst;
 ///
 /// assert_eq!(unsafe { conjure_zst::<()>() }, ());
 /// assert_eq!(unsafe { conjure_zst::<[i32; 0]>() }, []);
 /// ```
 ///
 /// [inhabited]: https://doc.rust-lang.org/reference/glossary.html#inhabited
-#[unstable(feature = "mem_conjure_zst", issue = "95383")]
-#[rustc_const_unstable(feature = "mem_conjure_zst", issue = "95383")]
+#[stable(feature = "mem_conjure_zst", since = "CURRENT_RUSTC_VERSION")]
+#[rustc_const_stable(feature = "mem_conjure_zst", since = "CURRENT_RUSTC_VERSION")]
+#[rustc_allow_const_fn_unstable(const_type_name)] // type_name() called only at run time
 pub const unsafe fn conjure_zst<T>() -> T {
     const_assert!(
         T::IS_ZST,

library/proc_macro/src/lib.rs

@@ -27,8 +27,8 @@
 #![feature(restricted_std)]
 #![feature(rustc_attrs)]
 #![feature(extend_one)]
-#![feature(mem_conjure_zst)]
 #![feature(f16)]
+#![cfg_attr(bootstrap, feature(mem_conjure_zst))]
 #![recursion_limit = "256"]
 #![allow(internal_features)]
 #![deny(ffi_unwind_calls)]

tests/ui/consts/std/conjure_zst.rs

@@ -1,5 +1,3 @@
-#![feature(mem_conjure_zst)]
-
 use std::{convert::Infallible, mem};
 
 const INVALID: Infallible = unsafe { mem::conjure_zst() };

tests/ui/consts/std/conjure_zst.stderr

@@ -1,5 +1,5 @@
 error[E0080]: evaluation panicked: aborted execution: attempted to instantiate uninhabited type `!`
-  --> $DIR/conjure_zst.rs:5:38
+  --> $DIR/conjure_zst.rs:3:38
    |
 LL | const INVALID: Infallible = unsafe { mem::conjure_zst() };
    |                                      ^^^^^^^^^^^^^^^^^^ evaluation of `INVALID` failed inside this call