1 files changed, 43 insertions, 0 deletions
diff --git a/src/test/ui/impl-trait/impl-generic-mismatch.stderr b/src/test/ui/impl-trait/impl-generic-mismatch.stderr
new file mode 100644
index 000000000..489afd761
--- /dev/null
+++ b/src/test/ui/impl-trait/impl-generic-mismatch.stderr
@@ -0,0 +1,43 @@
+error[E0643]: method `foo` has incompatible signature for trait
+  --> $DIR/impl-generic-mismatch.rs:8:12
+   |
+LL |     fn foo(&self, _: &impl Debug);
+   |                       ---------- declaration in trait here
+...
+LL |     fn foo<U: Debug>(&self, _: &U) { }
+   |            ^ expected `impl Trait`, found generic parameter
+   |
+help: try removing the generic parameter and using `impl Trait` instead
+   |
+LL -     fn foo<U: Debug>(&self, _: &U) { }
+LL +     fn foo(&self, _: &impl Debug) { }
+   |
+
+error[E0643]: method `bar` has incompatible signature for trait
+  --> $DIR/impl-generic-mismatch.rs:17:23
+   |
+LL |     fn bar<U: Debug>(&self, _: &U);
+   |            - declaration in trait here
+...
+LL |     fn bar(&self, _: &impl Debug) { }
+   |                       ^^^^^^^^^^ expected generic parameter, found `impl Trait`
+   |
+help: try changing the `impl Trait` argument to a generic parameter
+   |
+LL |     fn bar<U: Debug>(&self, _: &U) { }
+   |           ++++++++++            ~
+
+error[E0643]: method `hash` has incompatible signature for trait
+  --> $DIR/impl-generic-mismatch.rs:28:33
+   |
+LL |     fn hash(&self, hasher: &mut impl Hasher) {}
+   |                                 ^^^^^^^^^^^ expected generic parameter, found `impl Trait`
+   |
+  ::: $SRC_DIR/core/src/hash/mod.rs:LL:COL
+   |
+LL |     fn hash<H: Hasher>(&self, state: &mut H);
+   |             - declaration in trait here
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0643`.