[Bug libstdc++/116903] c++ regex accepts } and ] as a literal character.

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116903

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I think that's a valid ECMAScript regular expression.

Try alert(RegExp("a{0}}").test("}"));  in your browser console.