1 files changed, 33 insertions, 0 deletions
diff --git a/tests/ui/span/issue-23827.rs b/tests/ui/span/issue-23827.rs
new file mode 100644
index 00000000000..6b065bf6cbf
--- /dev/null
+++ b/tests/ui/span/issue-23827.rs
@@ -0,0 +1,33 @@
+// Regression test for #23827
+
+#![feature(fn_traits, unboxed_closures)]
+
+pub struct Prototype {
+    pub target: u32
+}
+
+trait Component {
+    fn apply(self, e: u32);
+}
+
+impl<C: Component> Fn<(C,)> for Prototype {
+    extern "rust-call" fn call(&self, (comp,): (C,)) -> Prototype {
+        comp.apply(self.target);
+        *self
+    }
+}
+
+impl<C: Component> FnMut<(C,)> for Prototype {
+    extern "rust-call" fn call_mut(&mut self, (comp,): (C,)) -> Prototype {
+        Fn::call(*&self, (comp,))
+    }
+}
+
+impl<C: Component> FnOnce<(C,)> for Prototype {
+    //~^ ERROR E0046
+    extern "rust-call" fn call_once(self, (comp,): (C,)) -> Prototype {
+        Fn::call(&self, (comp,))
+    }
+}
+
+fn main() {}