1 files changed, 63 insertions, 0 deletions
diff --git a/tests/ui/nll/issue-24535-allow-mutable-borrow-in-match-guard.rs b/tests/ui/nll/issue-24535-allow-mutable-borrow-in-match-guard.rs
new file mode 100644
index 000000000..ccfc8937f
--- /dev/null
+++ b/tests/ui/nll/issue-24535-allow-mutable-borrow-in-match-guard.rs
@@ -0,0 +1,63 @@
+// run-pass
+// This test illustrates that under NLL, we can remove our overly
+// conservative approach for disallowing mutations of match inputs.
+
+// See further discussion on rust-lang/rust#24535,
+// rust-lang/rfcs#1006, and rust-lang/rfcs#107
+
+#![feature(if_let_guard)]
+
+fn main() {
+    rust_issue_24535();
+    rfcs_issue_1006_1();
+    rfcs_issue_1006_2();
+}
+
+fn rust_issue_24535() {
+    fn compare(a: &u8, b: &mut u8) -> bool {
+        a == b
+    }
+
+    let a = 3u8;
+
+    match a {
+        0 => panic!("nope"),
+        3 if compare(&a, &mut 3) => (),
+        _ => panic!("nope"),
+    }
+
+    match a {
+        0 => panic!("nope"),
+        3 if let true = compare(&a, &mut 3) => (),
+        _ => panic!("nope"),
+    }
+}
+
+fn rfcs_issue_1006_1() {
+    let v = vec!["1".to_string(), "2".to_string(), "3".to_string()];
+    match Some(&v) {
+        Some(iv) if iv.iter().any(|x| &x[..]=="2") => true,
+        _ => panic!("nope"),
+    };
+}
+
+fn rfcs_issue_1006_2() {
+    #[inline(always)]
+    fn check<'a, I: Iterator<Item=&'a i32>>(mut i: I) -> bool {
+        i.any(|&x| x == 2)
+    }
+
+    let slice = [1, 2, 3];
+
+    match 42 {
+        _ if slice.iter().any(|&x| x == 2) => { true },
+        _ => { panic!("nope"); }
+    };
+
+    // (This match is just illustrating how easy it was to circumvent
+    // the checking performed for the previous `match`.)
+    match 42 {
+        _ if check(slice.iter()) => { true },
+        _ => { panic!("nope"); }
+    };
+}