In file included from parser-cat.cc:34: ./parser.hh:173:1: warning: declaration does not declare anything [-Wmissing-declarations] enum { ^ In file included from parser-cat.cc:35: ./parser-glue.hh:284:29: error: no member named 'clamp' in namespace 'std' return std::clamp(v, min_v, max_v); ~~~~~^ ./parser-glue.hh:278:30: error: no return statement in constexpr function inline constexpr int param(unsigned int idx, ^ ./parser-glue.hh:384:29: error: no member named 'clamp' in namespace 'std' return std::clamp(v, min_v, max_v); ~~~~~^ ./parser-glue.hh:378:30: error: no return statement in constexpr function inline constexpr int collect1(unsigned int idx, ^ parser-cat.cc:530:22: error: case value evaluates to -1, which cannot be narrowed to type 'unsigned int' [-Wc++11-narrowing] case -1: ^