https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85472
Tim Shen <timshen at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |timshen at gcc dot gnu.org --- Comment #1 from Tim Shen <timshen at gcc dot gnu.org> --- As I cross checked, boost 1.66, libstdc++, and python3 have the same behavior, only libc++ is different from the rest. I haven't checked the ECMAScript spec, but I suspect that it describes the boost/libstdc++/python behavior, only because it's more efficient, not less confusing. I know exactly how libc++ produces this result. It creates an empty match_result during each repetition ("*" operator). It's less confusing but much slower.