Method realloc

cranelift/entity/src/list.rs:249–267

Reallocate a block to a different size class. Copy `elems_to_copy` elements from the old to the new block.

(
        &mut self,
        block: usize,
        from_sclass: SizeClass,
        to_sclass: SizeClass,
        elems_to_copy: usize,
    )

    ///
    /// Copy `elems_to_copy` elements from the old to the new block.
    fn realloc(
        &mut self,
        block: usize,
        from_sclass: SizeClass,
        to_sclass: SizeClass,
        elems_to_copy: usize,
    ) -> usize {
        debug_assert!(elems_to_copy <= sclass_size(from_sclass));
        debug_assert!(elems_to_copy <= sclass_size(to_sclass));
        let new_block = self.alloc(to_sclass);

        if elems_to_copy > 0 {
            let (old, new) = self.mut_slices(block, new_block);
            (&mut new[0..elems_to_copy]).copy_from_slice(&old[0..elems_to_copy]);
        }

        self.free(block, from_sclass);
        new_block
    }
}

impl<T: EntityRef + ReservedValue> EntityList<T> {