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-rw-r--r--tests/ui/macros/macro-at-most-once-rep-2018-rpass.rs50
1 files changed, 50 insertions, 0 deletions
diff --git a/tests/ui/macros/macro-at-most-once-rep-2018-rpass.rs b/tests/ui/macros/macro-at-most-once-rep-2018-rpass.rs
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+++ b/tests/ui/macros/macro-at-most-once-rep-2018-rpass.rs
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+// run-pass
+
+#![allow(unused_mut)]
+
+// Check that when `?` is followed by what looks like a Kleene operator (?, +, and *)
+// then that `?` is not interpreted as a separator. In other words, `$(pat)?+` matches `pat +`
+// or `+` but does not match `pat` or `pat ? pat`.
+
+// edition:2018
+
+macro_rules! foo {
+    // Check for `?`.
+    ($($a:ident)? ? $num:expr) => {
+        foo!($($a)? ; $num);
+    };
+    // Check for `+`.
+    ($($a:ident)? + $num:expr) => {
+        foo!($($a)? ; $num);
+    };
+    // Check for `*`.
+    ($($a:ident)? * $num:expr) => {
+        foo!($($a)? ; $num);
+    };
+    // Check for `;`, not a kleene operator.
+    ($($a:ident)? ; $num:expr) => {
+        let mut x = 0;
+
+        $(
+            x += $a;
+        )?
+
+        assert_eq!(x, $num);
+    };
+}
+
+pub fn main() {
+    let a = 1;
+
+    // Accept 0 repetitions.
+    foo!( ; 0);
+    foo!( + 0);
+    foo!( * 0);
+    foo!( ? 0);
+
+    // Accept 1 repetition.
+    foo!(a ; 1);
+    foo!(a + 1);
+    foo!(a * 1);
+    foo!(a ? 1);
+}