------- Comment #11 from redi at gcc dot gnu dot org 2010-06-26 10:33 ------- [class.static.data]/3 If a static data member is of const literal type, its declaration in the class definition can specify a brace-or-equal-initializer ... 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.
[basic.def.odr] explains what "used" means. The code is invalid, I don't think it does users a service to accept it. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44673
