T has a non-static data member or a direct or virtual base without a move assignment operator that is not trivially copyable;.... So the order of operations says that even though the equality operator has higher precedence, the parentheses in your statement force the assignment.... The point of making an assignment operator virtual is to allow you from the benefit of being able to override it to copy more fields.. If you don't want a class to be copied, for example, you have to define an empty copy constructor and assignment operator... of a virtual function has to.... However, where a class contains references or pointers to outside resources, the assignment operator should be... member function (and cannot be virtual).
...on the syntactic form of the left-hand operand of an assignment operator, but for one difficulty: function calls are permitted to return references.. The ‘is‘ operator compares the identity of two objects; the id() function returns an integer representing its identity... the assignment of new attributes.... There are some cases, such as a virtual assignment operator in the base class, where lazy evaluation cannot be done, so it cannot be mandated..