1 files changed, 14 insertions, 0 deletions
diff --git a/tests/ui/traits/next-solver/projection/param-env-trait-candidate-1.rs b/tests/ui/traits/next-solver/projection/param-env-trait-candidate-1.rs
new file mode 100644
index 000000000..b337c0673
--- /dev/null
+++ b/tests/ui/traits/next-solver/projection/param-env-trait-candidate-1.rs
@@ -0,0 +1,14 @@
+// check-pass
+// compile-flags: -Znext-solver
+
+// See https://github.com/rust-lang/trait-system-refactor-initiative/issues/1
+// a minimization of a pattern in core.
+fn next<T: Iterator<Item = U>, U>(t: &mut T) -> Option<U> {
+    t.next()
+}
+
+fn foo<T: Iterator>(t: &mut T) {
+    let _: Option<T::Item> = next(t);
+}
+
+fn main() {}