Method from

crates/data-structures/src/slim_slice.rs:371–387

(slice: SlimSliceBox<T>)

    impl<T> From<SlimSliceBox<T>> for Box<[T]> {
        #[inline]
        fn from(slice: SlimSliceBox<T>) -> Self {
            let slice = ManuallyDrop::new(slice);
            let (ptr, len) = slice.raw.split();
            // SAFETY: All paths to creating a `SlimSliceBox`
            // go through `SlimSliceBox::from_boxed_unchecked`
            // which requires a valid `Box<[T]>`.
            // The function also uses `Box::into_raw`
            // and the original length is kept.
            //
            // It therefore follows that if we reuse the same
            // pointer and length as given to us by a valid `Box<[T]>`,
            // we can use `Box::from_raw` to reconstruct the `Box<[T]>`.
            //
            // We also no longer claim ownership of the data pointed to by `ptr`
            // by virtue of `ManuallyDrop` preventing `Drop for SlimSliceBox<T>`.
            unsafe { Box::from_raw(slice_from_raw_parts_mut(ptr, len)) }
        }
    }
}