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

From cppreference.com
< cpp‎ | experimental‎ | function
C++
Experimental
Technical Specification
Filesystem library (filesystem TS)
Library fundamentals (library fundamentals TS)
Library fundamentals 2 (library fundamentals TS v2)
Library fundamentals 3 (library fundamentals TS v3)
Extensions for parallelism (parallelism TS)
Extensions for parallelism 2 (parallelism TS v2)
Extensions for concurrency (concurrency TS)
Extensions for concurrency 2 (concurrency TS v2)
Concepts (concepts TS)
Ranges (ranges TS)
Reflection (reflection TS)
Mathematical special functions (special functions TR)
Experimental Non-TS
Pattern Matching
Linear Algebra
std::execution
Contracts
2D Graphics
Library fundamentals
Polymorphic allocator library
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 <> (library fundamentals TS v3)

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
3) Destroys the target of *this. *this is empty after the call. The memory resource returned by get_memory_resource()
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
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)

Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/experimental/function/operator%3D&oldid=154959