http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52136
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-02-06 14:24:39 UTC --- (In reply to comment #4) > I am not really sure to understand why friend class should impact his parent > but if g++ respects the standard, why not... It doesn't "impact his parent" Read comment 2 again. To access a protected non-static member you must do so though an object expression of the derived type, because in the expression 'p->address::m' you only know if 'm' is a member of a 'mailbox' object when 'p' has type 'mailbox*' But for a static member that is irrelevant, the static member just exists independently of any 'mailbox' or 'address' instance, so if mailboxField can access members of 'mailbox' then it can access the static member, and it doesn't matter if you refer to it as 'mailbox::parseNext' or 'address::parseNext' because both refer to the exact same entity.