From aeceeca60ccf204abb391424f914dfd0882a86cd Mon Sep 17 00:00:00 2001
From: Daniel Joyce <daniel.a.joyce@gmail.com>
Date: Thu, 11 Jul 2024 07:57:08 -0700
Subject: [PATCH] Added is_interned method which returns a bool

* Returns true if value already interned.
* Added simple test as well.
---
 src/boxedset.rs |  6 ++++++
 src/intern.rs   | 22 ++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/src/boxedset.rs b/src/boxedset.rs
index 15c98ec..4cf4837 100644
--- a/src/boxedset.rs
+++ b/src/boxedset.rs
@@ -44,6 +44,12 @@ impl<P: deepsize::DeepSizeOf + ?Sized> deepsize::DeepSizeOf for HashSet<Box<P>>
 }
 
 impl<P: Deref + Eq + Hash> HashSet<P> {
+    pub fn contains<Q: ?Sized + Hash + Eq>(&mut self, k: &Q) -> bool
+    where
+        P: Borrow<Q>,
+    {
+        self.0.contains_key(k)
+    }
     pub fn get<'a, Q: ?Sized + Eq + Hash>(&'a self, key: &Q) -> Option<&'a P>
     where
         P::Target: Borrow<Q>,
diff --git a/src/intern.rs b/src/intern.rs
index 3ed38f9..fd99f3a 100644
--- a/src/intern.rs
+++ b/src/intern.rs
@@ -43,6 +43,16 @@ use tinyset::Fits64;
 /// assert_eq!(y, Intern::from("world"));
 /// assert_eq!(&*x, "hello"); // dereference a Intern like a pointer
 /// ```
+///
+/// Checking if an object is already interned
+///
+/// ```rust
+/// 
+/// use internment::Intern;
+///
+/// let x = Intern::new("Fortunato");
+/// assert!(Intern::is_interned("Fortunato"));
+/// ```
 #[test]
 fn like_doctest_intern() {
     let x = Intern::new("hello".to_string());
@@ -51,6 +61,9 @@ fn like_doctest_intern() {
     assert_eq!(x, Intern::from_ref("hello"));
     assert_eq!(y, Intern::from_ref("world"));
     assert_eq!(&*x, "hello"); // dereference a Intern like a pointer\
+    let _ = Intern::new("Fortunato");
+    assert!(Intern::is_interned(&"Fortunato"));
+    assert!(!Intern::is_interned(&"Montresor"));
 }
 
 #[cfg_attr(docsrs, doc(cfg(feature = "intern")))]
@@ -224,6 +237,15 @@ impl<T: Eq + Hash + Send + Sync + 'static> Intern<T> {
             Intern { pointer: p }
         })
     }
+    /// Check if a value already is interned.
+    ///
+    /// If this value has previously been interned, return true, else returns false
+    pub fn is_interned<'a, Q: ?Sized + Eq + Hash + 'a>(val: &'a Q) -> bool
+    where
+        &'static T: Borrow<Q> + From<&'a Q>,
+    {
+        INTERN_CONTAINERS.with(|m: &mut HashSet<&'static T>| -> bool { m.contains(val) })
+    }
 }
 impl<T: Eq + Hash + Send + Sync + 'static + ?Sized> Intern<T> {
     /// Get a long-lived reference to the data pointed to by an `Intern`, which