https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67342
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution|--- |INVALID
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The compiler is correct, see [class.copy]/11.
B(B&&) is defaulted, so is defined as deleted, and "A defaulted move
constructor that is defined as deleted is ignored by overload resolution"