[Bug libstdc++/123758] warning: base class ‘class std::polyfunc::_Mo_base’ should be explicitly initialized in the copy constructor [-Wextra]

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123758

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
No, GCC doesn't warn about redundant initialization, certainly not for base
classes.

The optimizer will remove the dead store, but won't warn about it.