Merge pull request #1440 from multiversx/remove-maybe-uninit

remove maybe uninit

framework/base/src/lib.rs

@@ -3,8 +3,6 @@
 #![feature(exhaustive_patterns)]
 #![feature(try_trait_v2)]
 #![feature(control_flow_enum)]
-#![feature(maybe_uninit_uninit_array)]
-#![feature(maybe_uninit_array_assume_init)]
 #![feature(negative_impls)]
 #![feature(generic_const_exprs)]
 #![allow(incomplete_features)]

framework/base/src/types/managed/wrapped/managed_vec.rs

@@ -1,3 +1,4 @@
+use super::EncodedManagedVecItem;
 use crate::{
     abi::{TypeAbi, TypeDescriptionContainer, TypeName},
     api::{ErrorApiImpl, InvalidSliceError, ManagedTypeApi},
@@ -12,9 +13,14 @@ use crate::{
     },
 };
 use alloc::vec::Vec;
-use core::{borrow::Borrow, cmp::Ordering, fmt::Debug, iter::FromIterator, marker::PhantomData};
-
-use super::EncodedManagedVecItem;
+use core::{
+    borrow::Borrow,
+    cmp::Ordering,
+    fmt::Debug,
+    iter::FromIterator,
+    marker::PhantomData,
+    mem::{transmute_copy, ManuallyDrop, MaybeUninit},
+};
 
 pub(crate) const INDEX_OUT_OF_RANGE_MSG: &[u8] = b"ManagedVec index out of range";
 
@@ -147,12 +153,14 @@ where
             return None;
         }
 
-        let mut result_uninit = core::mem::MaybeUninit::<T::Ref<'_>>::uninit_array();
+        let mut result_uninit =
+            unsafe { MaybeUninit::<[MaybeUninit<T::Ref<'_>>; N]>::uninit().assume_init() };
+
         for (index, value) in self.iter().enumerate() {
             result_uninit[index].write(value);
         }
 
-        let result = unsafe { core::mem::MaybeUninit::array_assume_init(result_uninit) };
+        let result = unsafe { transmute_copy(&ManuallyDrop::new(result_uninit)) };
         Some(result)
     }
 

framework/scenario/tests/managed_vec_test.rs

@@ -97,6 +97,25 @@ fn test_into_vec() {
     assert_eq!(vec, managed_vec.into_vec());
 }
 
+#[test]
+fn test_to_array_of_refs() {
+    let mut vec = ManagedVec::<StaticApi, i32>::new();
+    for i in 0..10 {
+        vec.push(i);
+    }
+
+    let refs: Option<[i32; 20]> = vec.to_array_of_refs();
+    assert!(refs.is_none());
+
+    let refs: Option<[i32; 10]> = vec.to_array_of_refs();
+    assert!(refs.is_some());
+
+    let refs = refs.unwrap();
+    for (i, &item) in refs.iter().enumerate() {
+        assert_eq!(item, i as i32);
+    }
+}
+
 #[test]
 fn test_take_u64() {
     let mut vec = Vec::<u64>::new();