summaryrefslogtreecommitdiffstats
path: root/src/test/ui/macros/macro-at-most-once-rep-2018-rpass.rs
diff options
context:
space:
mode:
Diffstat (limited to 'src/test/ui/macros/macro-at-most-once-rep-2018-rpass.rs')
-rw-r--r--src/test/ui/macros/macro-at-most-once-rep-2018-rpass.rs50
1 files changed, 50 insertions, 0 deletions
diff --git a/src/test/ui/macros/macro-at-most-once-rep-2018-rpass.rs b/src/test/ui/macros/macro-at-most-once-rep-2018-rpass.rs
new file mode 100644
index 000000000..b37f38530
--- /dev/null
+++ b/src/test/ui/macros/macro-at-most-once-rep-2018-rpass.rs
@@ -0,0 +1,50 @@
+// 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);
+}