[Bug c++/49198] GCC generates spurious "has incomplete type" errors

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49198

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |INVALID
            Summary|[4.5/4.6/4.7 Regression]    |GCC generates spurious "has
                   |GCC generates spurious "has |incomplete type" errors
                   |incomplete type" errors     |

--- Comment #2 from Jason Merrill <jason at gcc dot gnu.org> 2011-05-27 21:05:25 UTC ---
The instantiation is being triggered by argument-dependent lookup.  When we see
FT(F), the associated classes for the argument F are the associated classes for
S<IC>*, or S<IC>, so we instantiate S<IC> to get any friend declarations.

If you change the call to ::FT(F), no argument-dependent lookup is done, so the
instantiation is not triggered.