[Bug c++/84075] [10/11/12/13 Regression] Template parameter not resolved: invalid application of ‘sizeof’ to incomplete type ‘boost::serialization::U’

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84075

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |10.5
                 CC|                            |ppalka at gcc dot gnu.org
            Summary|Template parameter not      |[10/11/12/13 Regression]
                   |resolved: invalid           |Template parameter not
                   |application of ‘sizeof’ to  |resolved: invalid
                   |incomplete type             |application of ‘sizeof’ to
                   |‘boost::serialization::U’   |incomplete type
                   |                            |‘boost::serialization::U’

--- Comment #12 from Patrick Palka <ppalka at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #11)
> (In reply to ensadc from comment #4)
> > Further reduced:
> > 
> > template < int > struct b { };
> > template < typename n > struct g {
> >   typedef b< sizeof(n) > l;
> > };
> > template < typename h, typename = typename g< h >::l > class aa {};
> > template < typename h, typename bz >
> > void bj(aa< h, bz >, int);
> > template < template < class > class ct > void bj(ct< class U >);
> > void f() {
> >   bj(aa<int>(), 0);
> > }
> > ----
> 
> Hmm, it comes with -std=c++11 and -std=c++14 but not -std=c++17.

Started to be rejected (with -std=c++17) since the introduction of
-fnew-ttp-matching r7-5537-g31bfc9b9dd65ec