1 files changed, 44 insertions, 0 deletions
diff --git a/tests/ui/impl-trait/equality2.rs b/tests/ui/impl-trait/equality2.rs
new file mode 100644
index 00000000000..2e325867da8
--- /dev/null
+++ b/tests/ui/impl-trait/equality2.rs
@@ -0,0 +1,44 @@
+#![feature(specialization)] //~ WARN the feature `specialization` is incomplete
+
+trait Foo: Copy + ToString {}
+
+impl<T: Copy + ToString> Foo for T {}
+
+fn hide<T: Foo>(x: T) -> impl Foo {
+    x
+}
+
+trait Leak: Sized {
+    type T;
+    fn leak(self) -> Self::T;
+}
+impl<T> Leak for T {
+    default type T = ();
+    default fn leak(self) -> Self::T { panic!() }
+}
+impl Leak for i32 {
+    type T = i32;
+    fn leak(self) -> i32 { self }
+}
+
+fn main() {
+    let _: u32 = hide(0_u32);
+    //~^ ERROR mismatched types
+    //~| expected type `u32`
+    //~| found opaque type `impl Foo`
+    //~| expected `u32`, found opaque type
+
+    let _: i32 = Leak::leak(hide(0_i32));
+    //~^ ERROR mismatched types
+    //~| expected type `i32`
+    //~| found associated type `<impl Foo as Leak>::T`
+    //~| expected `i32`, found associated type
+
+    let mut x = (hide(0_u32), hide(0_i32));
+    x = (x.1,
+    //~^ ERROR mismatched types
+    //~| expected `u32`, found `i32`
+         x.0);
+    //~^ ERROR mismatched types
+    //~| expected `i32`, found `u32`
+}