https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94117
Nathan Sidwell <nathan at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Ever confirmed|0 |1 Status|UNCONFIRMED |NEW Last reconfirmed| |2020-03-10 --- Comment #3 from Nathan Sidwell <nathan at gcc dot gnu.org> --- This is the error that should be emitted (modulo the argument type being _Iterator) devvm2772:6>./cc1plus -fmodule-header -quiet b_a.H In file included from b_a.H:1: b.h:10:69: error: call to 'static void _Iterator<_Const>::mover(const int&)' uses the default argument for parameter 1, which is not yet defined 10 | friend void move (const _Iterator &arg) noexcept (noexcept (mover ()))