[over.assign]

# 12 Overloading [[over]](./#over)

## 12.4 Overloaded operators [[over.oper]](over.oper#over.assign)

### 12.4.3 Binary operators [[over.binary]](over.binary#over.assign)

#### 12.4.3.2 Simple assignment [over.assign]

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/overloading.tex#L3566)

A [*simple assignment operator function*](#def:operator_function,simple_assignment "12.4.3.2 Simple assignment [over.assign]") is a binary operator function named operator=[.](#1.sentence-1)

A simple assignment operator function shall be a non-static member function[.](#1.sentence-2)

[*Note [1](#note-1)*:

Because only standard conversion sequences are considered when converting
to the left operand of an assignment operation ([[over.best.ics]](over.best.ics "12.2.4.2 Implicit conversion sequences")),
an expression x = y with a subexpression x of class type
is always interpreted as x.operator=(y)[.](#1.sentence-3)

— *end note*]

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/overloading.tex#L3577)

[*Note [2](#note-2)*:

Since a copy assignment operator is implicitly declared for a class
if not declared by the user ([[class.copy.assign]](class.copy.assign "11.4.6 Copy/move assignment operator")),
a base class assignment operator function is always hidden by
the copy assignment operator function of the derived class[.](#2.sentence-1)

— *end note*]

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/overloading.tex#L3585)

[*Note [3](#note-3)*:

Any assignment operator function, even the copy and move assignment operators,
can be virtual[.](#3.sentence-1)

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 overrideB's virtual copy/move assignment operator[.](#3.sentence-2)

[*Example [1](#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); // 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*]

— *end note*]