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std::experimental::function::operator=(3) C++ Standard Libary std::experimental::function::operator=(3)

NAME

std::experimental::function::operator= - std::experimental::function::operator=

Synopsis


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


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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2024.06.10 http://cppreference.com