Account for identity substituted items in symbol mangling

1 files changed, 16 insertions, 0 deletions

diff --git a/tests/coverage/generic-unused-impl.rs b/tests/coverage/generic-unused-impl.rs
new file mode 100644
index 00000000000..e44b1ca8a1d
--- /dev/null
+++ b/tests/coverage/generic-unused-impl.rs
@@ -0,0 +1,16 @@
+trait Foo {
+    type Assoc;
+
+    fn from(s: Self::Assoc) -> Self;
+}
+
+struct W<T>(T);
+
+impl<T: Foo> From<[T::Assoc; 1]> for W<T> {
+    fn from(from: [T::Assoc; 1]) -> Self {
+        let [item] = from;
+        W(Foo::from(item))
+    }
+}
+
+fn main() {}