Annex D (normative) Compatibility features [depr]

D.2 Implicit declaration of copy functions [depr.impldec]

The implicit definition of a copy constructor as defaulted is deprecated if the class has a user-declared copy assignment operator or a user-declared destructor. The implicit definition of a copy assignment operator as defaulted is deprecated if the class has a user-declared copy constructor or a user-declared destructor ([class.dtor], [class.copy]). In a future revision of this International Standard, these implicit definitions could become deleted ([dcl.fct.def]).