refactor: replace assume_every_elements_are_initialized with `Box::…

…<[T]>::assume_init`

package/origlang-slice-in-box/src/lib.rs

@@ -9,7 +9,7 @@ pub fn create_initialized_boxed_slice<I>(len: usize, mut create_element: impl Fn
         e.write(create_element(i));
     }
 
-    unsafe { assume_every_elements_are_initialized(slice) }
+    unsafe { slice.assume_init() }
 }
 
 pub fn try_create_initialized_boxed_slice<I, E>(len: usize, mut try_create_element: impl FnMut(usize) -> Result<I, E>) -> Result<BoxedSlice<I>, E> {
@@ -18,13 +18,5 @@ pub fn try_create_initialized_boxed_slice<I, E>(len: usize, mut try_create_eleme
         e.write(try_create_element(i)?);
     }
 
-    Ok(unsafe { assume_every_elements_are_initialized(slice) })
-}
-
-unsafe fn assume_every_elements_are_initialized<I>(half_baked_slice_in_box: BoxedSlice<MaybeUninit<I>>) -> BoxedSlice<I> {
-    let ptr = Box::into_raw(half_baked_slice_in_box);
-    // SAFETY: caller must initialize elements in the fed MaybeUninit-slice.
-    let slice = ptr as *mut [I];
-
-    unsafe { Box::from_raw(slice) }
+    Ok(unsafe { slice.assume_init() })
 }