Add Comparator blanking implementation for smart pointers

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "skl"
-version = "0.13.0"
+version = "0.13.1"
 edition = "2021"
 rust-version = "1.56.0"
 repository = "https://github.com/al8n/skl"

README.md

@@ -28,14 +28,14 @@
 
     ```toml
     [dependencies]
-    skl = "0.12"
+    skl = "0.13"
     ```
 
 - Enable memory map backend
 
     ```toml
     [dependencies]
-    skl = { version = "0.12", features = ["memmap"] }
+    skl = { version = "0.13", features = ["memmap"] }
     ```
 
 ## Features

src/lib.rs

@@ -97,6 +97,54 @@ pub trait Comparator: core::fmt::Debug {
     Q: ?Sized + PartialOrd<&'a [u8]>;
 }
 
+impl<C: Comparator> Comparator for std::sync::Arc<C> {
+  #[inline]
+  fn compare(&self, a: &[u8], b: &[u8]) -> cmp::Ordering {
+    (**self).compare(a, b)
+  }
+
+  #[inline]
+  fn contains<'a, Q>(&self, range: &impl RangeBounds<Q>, key: &'a [u8]) -> bool
+  where
+    &'a [u8]: PartialOrd<Q>,
+    Q: ?Sized + PartialOrd<&'a [u8]>,
+  {
+    (**self).contains(range, key)
+  }
+}
+
+impl<C: Comparator> Comparator for std::rc::Rc<C> {
+  #[inline]
+  fn compare(&self, a: &[u8], b: &[u8]) -> cmp::Ordering {
+    (**self).compare(a, b)
+  }
+
+  #[inline]
+  fn contains<'a, Q>(&self, range: &impl RangeBounds<Q>, key: &'a [u8]) -> bool
+  where
+    &'a [u8]: PartialOrd<Q>,
+    Q: ?Sized + PartialOrd<&'a [u8]>,
+  {
+    (**self).contains(range, key)
+  }
+}
+
+impl<C: Comparator> Comparator for std::boxed::Box<C> {
+  #[inline]
+  fn compare(&self, a: &[u8], b: &[u8]) -> cmp::Ordering {
+    (**self).compare(a, b)
+  }
+
+  #[inline]
+  fn contains<'a, Q>(&self, range: &impl RangeBounds<Q>, key: &'a [u8]) -> bool
+  where
+    &'a [u8]: PartialOrd<Q>,
+    Q: ?Sized + PartialOrd<&'a [u8]>,
+  {
+    (**self).contains(range, key)
+  }
+}
+
 /// Ascend is a comparator that compares byte slices in ascending order.
 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
 pub struct Ascend;