[Bug c++/47942] Not possible to initialize a shared_ptr with a class defined in function scope, inheriting from a global scope base class

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47942

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-03-01 
13:45:26 UTC ---
(In reply to comment #2)
> Your options are either to use C++0x mode (classes without linkage can be used
> as template arguments in C++0x) or to upcast the pointer

It seems that the change to allow local types as template args (see
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm for the
proposal) was implemented in GCC 4.5, so you can't rely on that in 4.4

So the best option is:

    return BasePtr(static_cast<Base*>(new InlineImpl));