1 files changed, 22 insertions, 0 deletions
diff --git a/src/test/ui/nll/issue-52057.rs b/src/test/ui/nll/issue-52057.rs
new file mode 100644
index 000000000..98f49fe8f
--- /dev/null
+++ b/src/test/ui/nll/issue-52057.rs
@@ -0,0 +1,22 @@
+// Regression test for #52057. There is an implied bound
+// that `I: 'a` where `'a` is the lifetime of `self` in `parse_first`;
+// but to observe that, one must normalize first.
+//
+// run-pass
+
+pub trait Parser {
+    type Input;
+
+    fn parse_first(input: &mut Self::Input);
+}
+
+impl<'a, I, P: ?Sized> Parser for &'a mut P
+where
+    P: Parser<Input = I>,
+{
+    type Input = I;
+
+    fn parse_first(_: &mut Self::Input) {}
+}
+
+fn main() {}