[Bug c++/80830] ice in tsubst_copy, at cp/pt.c:14569

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80830

--- Comment #1 from David Binderman <dcb314 at hotmail dot com> ---
Reduced code, although it doesn't look like legal C++ to me:

class a;
template < b > void operator<<(a , ;

class {        friend operator<<(a , ;          
template < int = 3 > class c {         
friend operator<<<>(, c ;           

c<> d({