1 files changed, 52 insertions, 0 deletions
diff --git a/src/test/ui/suggestions/impl-trait-with-missing-bounds.rs b/src/test/ui/suggestions/impl-trait-with-missing-bounds.rs
new file mode 100644
index 000000000..949b23600
--- /dev/null
+++ b/src/test/ui/suggestions/impl-trait-with-missing-bounds.rs
@@ -0,0 +1,52 @@
+// The double space in `impl  Iterator` is load bearing! We want to make sure we don't regress by
+// accident if the internal string representation changes.
+#[rustfmt::skip]
+fn foo(constraints: impl  Iterator) {
+    for constraint in constraints {
+        qux(constraint);
+//~^ ERROR `<impl Iterator as Iterator>::Item` doesn't implement `Debug`
+    }
+}
+
+fn bar<T>(t: T, constraints: impl Iterator) where T: std::fmt::Debug {
+    for constraint in constraints {
+        qux(t);
+        qux(constraint);
+//~^ ERROR `<impl Iterator as Iterator>::Item` doesn't implement `Debug`
+    }
+}
+
+fn baz(t: impl std::fmt::Debug, constraints: impl Iterator) {
+    for constraint in constraints {
+        qux(t);
+        qux(constraint);
+//~^ ERROR `<impl Iterator as Iterator>::Item` doesn't implement `Debug`
+    }
+}
+
+fn bat<I, T: std::fmt::Debug>(t: T, constraints: impl Iterator, _: I) {
+    for constraint in constraints {
+        qux(t);
+        qux(constraint);
+//~^ ERROR `<impl Iterator as Iterator>::Item` doesn't implement `Debug`
+    }
+}
+
+fn bak(constraints: impl  Iterator + std::fmt::Debug) {
+    for constraint in constraints {
+        qux(constraint);
+//~^ ERROR `<impl Iterator + std::fmt::Debug as Iterator>::Item` doesn't implement
+    }
+}
+
+#[rustfmt::skip]
+fn baw<>(constraints: impl Iterator) {
+    for constraint in constraints {
+        qux(constraint);
+//~^ ERROR `<impl Iterator as Iterator>::Item` doesn't implement `Debug`
+    }
+}
+
+fn qux(_: impl std::fmt::Debug) {}
+
+fn main() {}