https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84262
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Serguei Kolos from comment #0) > According to the article 9.4.2/4 of the C++ standard the code is probably > missing definitions of the c1, c2 and c3 constants: > > "If a static data member is of const integral or const enumeration type, its > declaration in the class definition can specify a constant initializer which > shall be an integral constant expression (5.19). In that case, the member > can appear in integral constant expressions within its scope. The member > shall still be defined in a namespace scope if it is used in the program and > the namespace scope definition shall not contain an initializer." Right. https://isocpp.org/wiki/faq/ctors#link-errs-static-data-mems > But what bothers me is the fact that the same (seemingly bogus) code > compiles fine with -OX flag. Is that normal? Yes, see https://gcc.gnu.org/wiki/VerboseDiagnostics#missing_static_const_definition
