https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109397
catsith at me dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |DUPLICATE
Status|UNCONFIRMED |RESOLVED
--- Comment #3 from catsith at me dot com ---
Allow me to resolve this as duplicate. As per other comments, the workaround is
to use type traits and std::enable_if_t instead of concept/requires, or to
include another constraint, e.g.
template<std::derived_from<type_c> _type_c, typename _arg>
requires streamable<_arg, type_b>
friend type_c &operator<<(_type_c &, _arg &&)
*** This bug has been marked as a duplicate of bug 99599 ***
