https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95932
--- Comment #1 from Haoxin Tu <haoxintu at gmail dot com> ---
Add a more meaningful case.
$cat p.cc
template <class> class a {};
template <template <class> >
struct a < class b{}, struct b {}>;
$g++ p.cc
p.cc:2:28: error: expected ‘class’ or ‘typename’ before ‘>’ token
2 | template <template <class> >
| ^
p.cc:3:19: error: types may not be defined in template arguments
3 | struct a < class b{}, struct b {}>;
| ^
p.cc:3:30: internal compiler error: in redeclare_class_template, at
cp/pt.c:6231
3 | struct a < class b{}, struct b {}>;
| ^
0x6be12f redeclare_class_template(tree_node*, tree_node*, tree_node*)
../../gcc/cp/pt.c:6231
...
While in Clang
$clang++ p.cc
p.cc:2:28: error: template template parameter requires 'class' after the
parameter list
template <template <class> >
^
class
p.cc:3:18: error: 'b' cannot be defined in a type specifier
struct a < class b{}, struct b {}>;
^
2 errors generated.
I guess this is also a possible issue that users may encounter in programming,
but it makes GCC crashed.
