https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98859
Bug ID: 98859 Summary: pedantic error on use of __VA_OPT__ before C++20 is unnecessary and counterproductive Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: richard-gccbugzilla at metafoo dot co.uk Target Milestone: --- There's no good way in ISO C or C++ to express what the GNU ,##__VA_ARGS__ extension does prior to the addition of __VA_OPT__. However, code targeting new compilers (that doesn't want to use GNU C / GNU C++) cannot reliably use __VA_OPT__ instead of the comma paste extension, because GCC's -pedantic-errors mode rejects it outside C++20. Such rejection is unnecessary: __VA_OPT__ is a reserved identifier in other language modes, so there is no conformance reason to issue a diagnostic on its use. I think it'd be useful for GCC to unconditionally allow using __VA_OPT__ in all language modes. (I'm changing Clang to do the same.)