refactor(cell): make SafeDeleter public

Author: Rexagon

src/cell/cell_impl/mod.rs

@@ -566,13 +566,16 @@ fn hash_index(descriptor: CellDescriptor, level: u8) -> u8 {
 
 // === Linear deleter ===
 
-struct SafeDeleter {
+/// Linear deleter for cell trees.
+pub struct SafeDeleter {
+    // TODO: Drop too large vector after competion?
     to_delete: std::cell::RefCell<Vec<CellInner>>,
     is_active: std::cell::Cell<bool>,
 }
 
 impl SafeDeleter {
-    fn retire(value: CellInner) {
+    /// Add cell into thread-local deleter queue.
+    pub fn retire(value: CellInner) {
         thread_local! {
             static DELETER: SafeDeleter = const {
                 SafeDeleter {

src/cell/mod.rs

@@ -13,7 +13,7 @@ pub use self::cell_context::{CellContext, CellParts, LoadMode};
 pub use self::cell_impl::rc::{Cell, CellInner, WeakCell};
 #[cfg(feature = "sync")]
 pub use self::cell_impl::sync::{Cell, CellInner, WeakCell};
-pub use self::cell_impl::{StaticCell, VirtualCellWrapper};
+pub use self::cell_impl::{SafeDeleter, StaticCell, VirtualCellWrapper};
 pub use self::lazy::{Lazy, LazyExotic};
 pub use self::slice::{
     CellSlice, CellSliceParts, CellSliceRange, DisplayCellSliceData, ExactSize, Load, LoadCell,