# std::experimental::function<R(Args...)>::operator=

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< cpp‎ | experimental‎ | function

function& operator=( const function& other ); | (1) | (library fundamentals TS)
function& operator=( function&& other ); | (2) | (library fundamentals TS)
function& operator=( std::nullptr_t ) noexcept; | (3) | (library fundamentals TS)
template< class F > function& operator=( F&& f ); | (4) | (library fundamentals TS)
| (5) |
template< class F > function& operator=( std::reference_wrapper<F> f ); |  | (library fundamentals TS)
template< class F > function& operator=( std::reference_wrapper<F> f ) noexcept; |  | (library fundamentals TS v3)

Assigns a new target to `std::experimental::function`. In the description below, let ALLOCATOR_OF(f) be the allocator specified in the construction of f, or the value of std::experimental::pmr::get_default_resource() (until library fundamentals TS v3)the default-constructed std::pmr::polymorphic_allocator<> value (library fundamentals TS v3) at the time of construction if no allocator was specified.

1) Assigns a copy of target of other, as if by executing function(std::allocator_arg, ALLOCATOR_OF(*this), other).swap(*this);.
2) Moves the target of other to *this, as if by executing function(std::allocator_arg, ALLOCATOR_OF(*this), std::move(other)).swap(*this);. other is in a valid state with an unspecified value.
3) Destroys the target of *this. *this is empty after the call. The memory resource returned by `get_memory_resource()` after the assignment is equivalent to the memory resource before the assignment, but the address may change.
4) Sets the target of *this to the callable f, as if by executing function(std::allocator_arg, ALLOCATOR_OF(*this),std::forward<F>(f)).swap(*this);. This operator does not participate in overload resolution unless f is Callable for argument types `Args...` and return type `R`.
5) Sets the target of *this to a copy of f, as if by executing function(std::allocator_arg, ALLOCATOR_OF(*this), f).swap(*this);.

### Parameters

other | - | another `std::experimental::function` object to copy or move from
f | - | a callable to initialize the target with
Type requirements
- `F` must meet the requirements of Callable.

### Return value

*this

### Exceptions

1,2,4) Exception thrown on needed allocation of the storage or initialization of the target of *this, if any.
5) (none)

### Notes

The move assignment operator may need to allocate storage if get_memory_resource() != other.get_memory_resource() (until library fundamentals TS v3)get_allocator() != other.get_allocator() (library fundamentals TS v3)

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