12 Overloading [over]

12.6 Overloaded operators [over.oper]

12.6.2 Binary operators [over.binary]

12.6.2.1 Simple assignment [over.ass]

A simple assignment operator function is a binary operator function named operator=.

A simple assignment operator function shall be a non-static member function.

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).

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]

[ Note

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.

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]

[ Note

Any assignment operator function, even the copy and move assignment operators, can be virtual.

For a derived class D with a base class B for which a virtual copy/move assignment has been declared, the copy/move assignment operator in D does not override B's virtual copy/move assignment operator.

[ Example

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);          // calls D::operator=(int)
  *bptr = 99;                   // ditto
  bptr->operator=(dobj2);       // calls D::operator=(const B&)
  *bptr = dobj2;                // ditto
  dobj1 = dobj2;                // calls implicitly-declared D::operator=(const D&)
}

— end example

]

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]