add tracking issue and unit testt

Author: fee1-dead

library/core/src/array/mod.rs

@@ -56,7 +56,7 @@ pub use iter::IntoIter;
 /// ```
 #[inline]
 #[stable(feature = "array_from_fn", since = "1.63.0")]
-#[rustc_const_unstable(feature = "const_array_from_fn", issue = "none")]
+#[rustc_const_unstable(feature = "const_array_from_fn", issue = "109341")]
 pub const fn from_fn<T, const N: usize, F>(cb: F) -> [T; N]
 where
     F: ~const FnMut(usize) -> T + ~const Destruct,
@@ -839,7 +839,7 @@ where
 /// not optimizing away.  So if you give it a shot, make sure to watch what
 /// happens in the codegen tests.
 #[inline]
-#[rustc_const_unstable(feature = "const_array_from_fn", issue = "none")]
+#[rustc_const_unstable(feature = "const_array_from_fn", issue = "109341")]
 const fn try_from_fn_erased<T, R>(
     buffer: &mut [MaybeUninit<T>],
     mut generator: impl ~const FnMut(usize) -> R + ~const Destruct,

library/core/src/ptr/mod.rs

@@ -486,7 +486,7 @@ mod mut_ptr;
 /// assert!(weak.upgrade().is_none());
 /// ```
 #[stable(feature = "drop_in_place", since = "1.8.0")]
-#[rustc_const_unstable(feature = "const_drop_in_place", issue = "none")]
+#[rustc_const_unstable(feature = "const_drop_in_place", issue = "109342")]
 #[lang = "drop_in_place"]
 #[allow(unconditional_recursion)]
 pub const unsafe fn drop_in_place<T: ?Sized + ~const Destruct>(to_drop: *mut T) {

library/core/tests/array.rs

@@ -376,6 +376,9 @@ fn cell_allows_array_cycle() {
 fn array_from_fn() {
     let array = core::array::from_fn(|idx| idx);
     assert_eq!(array, [0, 1, 2, 3, 4]);
+
+    const ARR: [usize; 5] = core::array::from_fn(const |idx| idx);
+    assert_eq!(ARR, [0, 1, 2, 3, 4]);
 }
 
 #[test]

library/core/tests/lib.rs

@@ -5,12 +5,14 @@
 #![feature(bigint_helper_methods)]
 #![feature(cell_update)]
 #![feature(const_align_offset)]
+#![feature(const_array_from_fn)]
 #![feature(const_assume)]
 #![feature(const_align_of_val_raw)]
 #![feature(const_black_box)]
 #![feature(const_bool_to_option)]
 #![feature(const_caller_location)]
 #![feature(const_cell_into_inner)]
+#![feature(const_closures)]
 #![feature(const_convert)]
 #![feature(const_for)]
 #![feature(const_hash)]
@@ -116,6 +118,7 @@
 #![feature(utf8_chunks)]
 #![feature(is_ascii_octdigit)]
 #![feature(get_many_mut)]
+#![allow(incomplete_features)]
 #![deny(unsafe_op_in_unsafe_fn)]
 #![deny(fuzzy_provenance_casts)]