1 files changed, 56 insertions, 0 deletions

diff --git a/tests/ui/issues/issue-18952.rs b/tests/ui/issues/issue-18952.rs
new file mode 100644
index 000000000..56378b59e
--- /dev/null
+++ b/tests/ui/issues/issue-18952.rs
@@ -0,0 +1,56 @@
+// This issue tests fn_traits overloading on arity.
+// run-pass
+
+#![feature(fn_traits)]
+#![feature(unboxed_closures)]
+
+struct Foo;
+
+impl Fn<(isize, isize)> for Foo {
+    extern "rust-call" fn call(&self, args: (isize, isize)) -> Self::Output {
+        println!("{:?}", args);
+        (args.0 + 1, args.1 + 1)
+    }
+}
+
+impl FnMut<(isize, isize)> for Foo {
+    extern "rust-call" fn call_mut(&mut self, args: (isize, isize)) -> Self::Output {
+        println!("{:?}", args);
+        (args.0 + 1, args.1 + 1)
+    }
+}
+
+impl FnOnce<(isize, isize)> for Foo {
+    type Output = (isize, isize);
+    extern "rust-call" fn call_once(self, args: (isize, isize)) -> Self::Output {
+        println!("{:?}", args);
+        (args.0 + 1, args.1 + 1)
+    }
+}
+
+impl Fn<(isize, isize, isize)> for Foo {
+    extern "rust-call" fn call(&self, args: (isize, isize, isize)) -> Self::Output {
+        println!("{:?}", args);
+        (args.0 + 3, args.1 + 3, args.2 + 3)
+    }
+}
+
+impl FnMut<(isize, isize, isize)> for Foo {
+    extern "rust-call" fn call_mut(&mut self, args: (isize, isize, isize)) -> Self::Output {
+        println!("{:?}", args);
+        (args.0 + 3, args.1 + 3, args.2 + 3)
+    }
+}
+impl FnOnce<(isize, isize, isize)> for Foo {
+    type Output = (isize, isize, isize);
+    extern "rust-call" fn call_once(self, args: (isize, isize, isize)) -> Self::Output {
+        println!("{:?}", args);
+        (args.0 + 3, args.1 + 3, args.2 + 3)
+    }
+}
+
+fn main() {
+    let foo = Foo;
+    assert_eq!(foo(1, 1), (2, 2));
+    assert_eq!(foo(1, 1, 1), (4, 4, 4));
+}