[Bug c++/53856] Default argument allowed on member defined outside of class template

["redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53856

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |rejects-valid
      Known to fail|                            |3.4.3, 4.1.2, 4.6.3, 4.8.0

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-07-04 16:43:53 UTC ---
Modifying the example to use a member template of a non-template, which I
believe *is* valid, gets rejected:

struct A
{
    template<typename T>
        struct B;
};

template<typename T = int>
struct A::B
{
    int i;
};

int main()
{
    A::B<int> b = { };
    return b.i;
}

bug.cc:8:11: error: default argument for template parameter for class enclosing
'struct A::B<T>'

This seems to be completely backwards, the invalid case is accepted and the
valid case rejected!

Comeau online rejects it for the same reason as the code in commnt 0 above:

"ComeauTest.c", line 6: error: a default template argument cannot be specified
on
          the declaration of a member of a class template outside of its class
  template<typename T = int>
                    ^

The wording is much better than G++'s, but I think the error is wrong, as it
talks about a member of a class template, whereas the code above is a member
template of a class. Not the same thing.

Clang++ and Solaris CC accept the modified version.