[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 #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The C++ standard references
Ecma International, ECMAScript2 Language Specification, Standard Ecma-262,
third edition, 1999