macro_rules! zero_or_one {($($a:literal)?) => {// { dg-error "invalid amount of matches for macro invocation. Expected between 0 and 1, got 2" }f();}}fnmain() {
zero_or_one!();
zero_or_one!(14);
zero_or_one!(125 12"gcc");// { dg-error "Failed to match any rule within macro" }}