https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69387
--- Comment #3 from Bernd Edlinger <bernd.edlinger at hotmail dot de> --- Oh, now I see, you mean: C++ Standard, Sec. 9.4.2 paragraph 4 says: 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. The member shall still be defined in a name-space scope if it is used in the program and the namespace scope definition shall not contain an initializer. right?