1 files changed, 33 insertions, 0 deletions
diff --git a/src/by_ptr.rs b/src/by_ptr.rs
new file mode 100644
index 0000000..b541f9e
--- /dev/null
+++ b/src/by_ptr.rs
@@ -0,0 +1,33 @@
+use std::ops::Deref;
+
+use super::traits::*;
+
+/// Wrapper struct for using pointer equality and hashes rather
+/// than pointed-to value equality and hashes.
+#[derive(Clone, Debug)]
+pub struct ByPtr<K>(K);
+
+impl<K: WeakElement> WeakElement for ByPtr<K> {
+    type Strong = K::Strong;
+
+    fn new(view: &Self::Strong) -> Self {
+        ByPtr(K::new(view))
+    }
+
+    fn view(&self) -> Option<Self::Strong> {
+        self.0.view()
+    }
+}
+
+impl<K: WeakElement> WeakKey for ByPtr<K>
+    where K::Strong: Deref
+{
+    type Key = *const <K::Strong as Deref>::Target;
+
+    fn with_key<F, R>(view: &Self::Strong, f: F) -> R
+        where F: FnOnce(&Self::Key) -> R
+    {
+        f(&(view.deref() as *const _))
+    }
+}
+