Impls Finalize, Trace for PhantomData.

Manishearth · Sep 24, 2017 · 763addb · 763addb
1 parent 470b6a8
commit 763addb
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diff --git a/gc/src/trace.rs b/gc/src/trace.rs
@@ -301,6 +301,11 @@ unsafe impl<T: Eq + Hash + Trace> Trace for LinkedList<T> {
     });
 }
 
+impl<T> Finalize for PhantomData<T> {}
+unsafe impl<T> Trace for PhantomData<T> {
+    unsafe_empty_trace!();
+}
+
 impl<T: Trace> Finalize for VecDeque<T> {}
 unsafe impl<T: Trace> Trace for VecDeque<T> {
     custom_trace!(this, {

diff --git a/gc/tests/phantom_data.rs b/gc/tests/phantom_data.rs
@@ -0,0 +1,12 @@
+extern crate gc;
+
+use std::marker::PhantomData;
+
+use gc::Gc;
+
+enum Uninhabited {}
+
+#[test]
+fn phantom_data() {
+    let _x: Gc<PhantomData<Uninhabited>> = Gc::new(PhantomData);
+}