[over.ass] (original) (raw)
12 Overloading [over]
12.4 Overloaded operators [over.oper]
12.4.3 Binary operators [over.binary]
12.4.3.2 Simple assignment [over.ass]
A simple assignment operator functionis a binary operator function named operator=.
A simple assignment operator function shall be a non-static member function.
[Note 1:
Because only standard conversion sequences are considered when converting to the left operand of an assignment operation ([over.best.ics]), an expression x = y with a subexpression x of class type is always interpreted as x.operator=(y).
— _end note_]
[Note 2:
Since a copy assignment operator is implicitly declared for a class if not declared by the user ([class.copy.assign]), a base class assignment operator function is always hidden by the copy assignment operator function of the derived class.
— _end note_]
[Note 3:
Any assignment operator function, even the copy and move assignment operators, can be virtual.
For a derived class D with a base class Bfor which a virtual copy/move assignment has been declared, the copy/move assignment operator in D does not overrideB's virtual copy/move assignment operator.
[Example 1: struct B { virtual int operator= (int);virtual B& operator= (const B&);};struct D : B { virtual int operator= (int);virtual D& operator= (const B&);}; D dobj1; D dobj2; B* bptr = &dobj1;void f() { bptr->operator=(99); *bptr = 99; bptr->operator=(dobj2); *bptr = dobj2; dobj1 = dobj2; } — _end example_]
— _end note_]