[Bug c++/60011] New: Compile error for legal exemplar from c++11 std [class.friend] 11.3.2

[peter at hurleysoftware dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60011

            Bug ID: 60011
           Summary: Compile error for legal exemplar from c++11 std
                    [class.friend] 11.3.2
           Product: gcc
           Version: 4.8.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: peter at hurleysoftware dot com

Created attachment 32003
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32003&action=edit
testcase

g++ 4.8.2 fails to compile the legal example from c++11 std specification,
section 11.3.2 [class.friend]:

"Declaring a class to be a friend implies that the names of private and
protected members from the class granting friendship can be accessed in the
base-specifiers and member declarations of the befriended class.
[ Example:

class A {
  class B { };
  friend class X;
};

struct X : A::B {  // OK: A::B accessible to friend
  A::B mx;         // OK: A::B accessible to member of friend
  class Y {
    A::B my;       // OK: A::B accessible to nested member of friend
  };
};

—end example ]"

Note specifically that the private nested class A::B is a valid base specifier
for the friend class X. However, g++ 4.8.2 issues the following error
diagnostic when A::B is used as the base specifier:

peter@thor:~/src/test/c++$ /opt/gcc-4.8.2/bin/g++ -c -std=c++11 nested.cpp
nested.cpp:3:8: error: ‘class A::B’ is private
  class B {};
        ^
nested.cpp:7:15: error: within this context
 struct X : A::B {
               ^