1 files changed, 20 insertions, 0 deletions
diff --git a/src/test/ui/mismatched_types/closure-arg-count-expected-type-issue-47244.fixed b/src/test/ui/mismatched_types/closure-arg-count-expected-type-issue-47244.fixed
new file mode 100644
index 000000000..efba0543b
--- /dev/null
+++ b/src/test/ui/mismatched_types/closure-arg-count-expected-type-issue-47244.fixed
@@ -0,0 +1,20 @@
+// Regression test for #47244: in this specific scenario, when the
+// expected type indicated 1 argument but the closure takes two, we
+// would (early on) create type variables for the type of `b`. If the
+// user then attempts to invoke a method on `b`, we would get an error
+// saying that the type of `b` must be known, which was not very
+// helpful.
+
+// run-rustfix
+
+use std::collections::HashMap;
+
+fn main() {
+    let mut m = HashMap::new();
+    m.insert("foo", "bar");
+
+    let _n = m.iter().map(|(_, b)| {
+        //~^ ERROR closure is expected to take a single 2-tuple
+        b.to_string()
+    });
+}