future< T >

The class template future provides a mechanism to access the result of asynchronous operations. More...

Public Member Functions
	future () noexcept=default
	future (future &&rhs) noexcept=default
	future (const future &)=delete
future &	operator= (const future &)=delete
future &	operator= (future &&rhs) noexcept=default
	~future ()=default
shared_future< T >	share () noexcept
T	get ()
	Get the result of asynchronyous operation stored in this future object. More...
void	wait () const
bool	valid () const noexcept
bool	is_ready () const
template<typename F >
void	notify (F &&notification)
template<typename E , typename F >
void	notify (E &&exec, F &&notification)
future	detach ()

Detailed Description

template<typename T>
class portable_concurrency::cxx14_v1::future< T >

The class template future provides a mechanism to access the result of asynchronous operations.

Constructor & Destructor Documentation

future() [1/3]

future ( )

defaultnoexcept

Constructs invalid future object

Postcondition

this->valid() == false

future() [2/3]

future ( future< T > &&  rhs )

defaultnoexcept

Move constructor

Postcondition

rhs.valid() == false

future() [3/3]

future ( const future< T > &  )

delete

Copy constructor is explicitly deleted. Future object is not copyable.

~future()

~future ( )

default

Destroys associated shared state and cancel not yet started operations.

Member Function Documentation

detach()

future detach

(

)

Prevents cancellation of the operations of this future value calculation on its destruction.

Postcondition

this->valid() == false

get()

T get

(

)

Get the result of asynchronyous operation stored in this future object.

If the value is not yet set block current thread and wait for it. The value stored in the future is moved to the caller.

Postcondition

this->valid() == false

is_ready()

bool is_ready

(

)

const

Checks if associated shared state is ready

notify() [1/2]

void notify	(	E &&	exec,
		F &&	notification
	)

Adds notification function to be called when this future object becomes ready.

Notification function must meet MoveConstructable, MoveAssignable and Callable (with signature void()) standard library requirements.

Both exec and notification objects are decay copied on the caller thread. Once this future object becomes ready post(exec, std::move(notification)) is executed on unspecified thread. Implementation provide strict guaranty that notification is scheduled for execution at most once. If this->is_ready() == true then notification is scheduled for execution immediatelly.

notify() [2/2]

void notify

(

F &&

notification

)

Adds notification function to be called when this future object becomes ready.

Equivalent to this->notify(inplace_executor, notification).

Note

Thread of notification execution is unspecified.

operator=() [1/2]

future& operator= ( const future< T > &  )

delete

Copy assignment operator is explicitly deleted. Future object is not copyable.

operator=() [2/2]

future& operator= ( future< T > &&  rhs )

defaultnoexcept

Move assignmet

Postcondition

rhs.valid() == false

share()

shared_future<T> share ( )

noexcept

Creates shared_future object and move ownership on the shared state associated to this object to it

Postcondition

this->valid() == false

valid()

bool valid ( ) const

noexcept

Checks if future has associated shared state

Note

All operations except this method, move assignment and destructor on an invalid future are UB.

wait()

void wait

(

)

const

Blocks curent thread until this future object becomes ready.