refactor: use MaybeUninit::uninit_array

There were some overlooked use cases of
`#![feature(const_maybe_uninit_uninit_array)]`.

Author: yvt

src/r3_core/src/bind.rs

@@ -1835,7 +1835,7 @@ where
     fn into_runtime_binder(self) -> Self::Runtime {
         unsafe {
             // `[T; N]::map` is unusable in `const fn` [ref:const_array_map]
-            let mut out: [MaybeUninit<Binder::Runtime>; LEN] = MaybeUninit::uninit_array();
+            let mut out = MaybeUninit::uninit_array();
             let this = MaybeUninit::new(self);
             // `for` loops are unusable in `const fn` [ref:const_for]
             let mut i = 0;

src/r3_core/src/utils/aligned_storage.rs

@@ -19,7 +19,7 @@ impl<const LEN: usize, const ALIGN: usize> Init for AlignedStorage<LEN, ALIGN>
 where
     elain::Align<ALIGN>: elain::Alignment,
 {
-    const INIT: Self = Self(elain::Align::NEW, [MaybeUninit::uninit(); LEN]);
+    const INIT: Self = Self(elain::Align::NEW, MaybeUninit::uninit_array());
 }
 
 #[cfg(test)]

src/r3_core/src/utils/for_times.rs

@@ -203,7 +203,7 @@ macro_rules! const_array_from_fn {
     ) => {{
         use core::mem::MaybeUninit;
         use $crate::utils::for_times::Nat;
-        let mut array = [MaybeUninit::uninit(); $len_value];
+        let mut array = MaybeUninit::uninit_array::<{$len_value}>();
 
         if array.len() != <$len as Nat>::N {
             unreachable!();

src/r3_core/src/utils/init.rs

@@ -35,7 +35,8 @@ impl<T: ?Sized> Init for PhantomData<T> {
 
 impl<T: Init, const LEN: usize> Init for [T; LEN] {
     const INIT: Self = {
-        let mut array = super::mem::uninit_array::<T, LEN>();
+        // `<[T; LEN]>::from_fn` is not `const fn` [ref:const_array_from_fn]
+        let mut array = mem::MaybeUninit::uninit_array();
 
         // `for` is unusable in `const fn` [ref:const_for]
         let mut i = 0;

src/r3_test_suite/src/kernel_benchmarks/timer_start.rs

@@ -39,8 +39,9 @@ impl<System: SupportedSystem> AppInner<System> {
             + ~const traits::CfgTask
             + ~const traits::CfgTimer,
     {
+        // `<[T; LEN]>::from_fn` is not `const fn` [ref:const_array_from_fn]
         let timers = {
-            let mut timers = [MaybeUninit::<StaticTimer<System>>::uninit(); 64];
+            let mut timers = MaybeUninit::uninit_array();
 
             let mut i = 0;
             // `for` is unusable in `const fn` [ref:const_for]

src/r3_test_suite/src/lib.rs

@@ -1,6 +1,8 @@
 #![feature(const_maybe_uninit_array_assume_init)]
 #![feature(const_fn_floating_point_arithmetic)]
+#![feature(const_maybe_uninit_uninit_array)]
 #![feature(maybe_uninit_array_assume_init)]
+#![feature(maybe_uninit_uninit_array)]
 #![feature(cfg_target_has_atomic)]
 #![feature(const_transmute_copy)]
 #![feature(const_refs_to_cell)]