std::promise

 

C++

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Thread support library

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thread (C++11)
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lock_guard (C++11) unique_lock (C++11) defer_lock_t try_to_lock_t adopt_lock_t (C++11) (C++11) (C++11)	lock (C++11) try_lock (C++11) defer_lock try_to_lock adopt_lock (C++11) (C++11) (C++11)
Condition variables
condition_variable (C++11)
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Futures
promise (C++11) future (C++11) shared_future (C++11) packaged_task (C++11) async (C++11)	launch (C++11) future_status (C++11) future_error (C++11) future_category (C++11) future_errc (C++11)

 

std::promise

Member functions

promise::promise

promise::~promise

promise::operator=

promise::swap

Getting the result

promise::get_future

Setting the result

promise::set_value

promise::set_value_at_thread_exit

promise::set_exception

promise::set_exception_at_thread_exit

 

Defined in header <future>
template< class T > class promise;	(1)	(since C++11)
template< class T > class promise<T&>;	(2)	(since C++11)
template<>          class promise<void>;	(3)	(since C++11)

The class template std::promise provides a facility to store a value that is later acquired asynchronously via a std::future object, that the std::promise can supply.

Member functions

(constructor)	constructs the promise object (public member function)
(destructor)	destructs the promise object (public member function)
operator=	assigns the shared state (public member function)
swap	swaps two promise objects (public member function)
Getting the result
get_future	returns a future associated with the promised result (public member function)
Setting the result
set_value	sets the result to specific value (public member function)
set_value_at_thread_exit	sets the result to specific value while delivering the notification only at thread exit (public member function)
set_exception	sets the result to indicate an exception (public member function)
set_exception_at_thread_exit	sets the result to indicate an exception while delivering the notification only at thread exit (public member function)

Non-member functions

std::swap(std::promise) (C++11)	specializes the std::swap algorithm (function template)

Helper classes

std::uses_allocator<std::promise> (C++11)	specializes the std::uses_allocator type trait (class template specialization)