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std::move_only_function::operator=

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move_only_function& operator=( move_only_function&& other );
(1) (since C++23)
move_only_function& operator=( const move_only_function& ) = delete;
(2) (since C++23)
move_only_function& operator=( std::nullptr_t ) noexcept;
(3) (since C++23)
template< class F >
move_only_function& operator=( F&& f );
(4) (since C++23)

Assigns a new target to std::move_only_function or destroys its target.

1) Moves the target of other to *this or destroys the target of *this (if any) if other is empty, by auto(std::move(other)).swap(*this). other is in a valid state with an unspecified value after move assignment.
2) Copy assignment operator is deleted. std::move_only_function does not satisfy CopyAssignable.
3) Destroys the current target if it exists. *this is empty after the call.
4) Sets the target of *this to the callable f, or destroys the current target if f is a null function pointer, a null pointer to member function, or an empty std::move_only_function, as if by executing move_only_function(std::forward<F>(f)).swap(*this);. This overload participates in overload resolution only if the constructor of move_only_function from F participates in overload resolution. The program is ill-formed or has undefined behavior if the selected constructor call is ill-formed or has undefined behavior.

Contents

[edit] Parameters

other - another std::move_only_function object to move the target of
f - a callable object to initialize the new target with

[edit] Return value

*this

[edit] Notes

It is intentional not to require the move assignment operator to be noexcept to leave room for an allocator-aware move_only_function in future.

move_only_function can be assigned from std::in_place_type<Fn> given it can be constructed from that argument.

[edit] See also

assigns a new target
(public member function of std::function<R(Args...)>) [edit]