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

[tkaminsk at gcc dot gnu.org via Gcc-bugs]

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

--- Comment #1 from Tomasz Kamiński <tkaminsk at gcc dot gnu.org> ---
> I think this should have `: _Mo_base()` on the copy constructor to avoid the 
> warning.

Yes, I agree. We do not want to copy storage. 
But I wonder if this will not dead store warning for this->_M_manage, that is
will be overriden by _M_copy.