1 files changed, 30 insertions, 0 deletions
diff --git a/tests/ui/half-open-range-patterns/half-open-range-pats-inclusive-dotdotdot-bad-syntax.rs b/tests/ui/half-open-range-patterns/half-open-range-pats-inclusive-dotdotdot-bad-syntax.rs
new file mode 100644
index 00000000000..526a797e9d6
--- /dev/null
+++ b/tests/ui/half-open-range-patterns/half-open-range-pats-inclusive-dotdotdot-bad-syntax.rs
@@ -0,0 +1,30 @@
+// Test that `...X` range-to patterns are syntactically invalid.
+//
+// See https://github.com/rust-lang/rust/pull/67258#issuecomment-565656155
+// for the reason why. To summarize, we might want to introduce `...expr` as
+// an expression form for splatting (or "untupling") in an expression context.
+// While there is no syntactic ambiguity with `...X` in a pattern context,
+// there's a potential confusion factor here, and we would prefer to keep patterns
+// and expressions in-sync. As such, we do not allow `...X` in patterns either.
+
+fn main() {}
+
+#[cfg(FALSE)]
+fn syntax() {
+    match scrutinee {
+        ...X => {} //~ ERROR range-to patterns with `...` are not allowed
+        ...0 => {} //~ ERROR range-to patterns with `...` are not allowed
+        ...'a' => {} //~ ERROR range-to patterns with `...` are not allowed
+        ...0.0f32 => {} //~ ERROR range-to patterns with `...` are not allowed
+    }
+}
+
+fn syntax2() {
+    macro_rules! mac {
+        ($e:expr) => {
+            let ...$e; //~ ERROR range-to patterns with `...` are not allowed
+        }
+    }
+
+    mac!(0);
+}