std::future

 

C++

Linguaggio

Concetti

Libreria di Utilità

Stringhe

Contenitori

Algoritmi

Iteratori

Libreria matematca

Input/output

Localizzazione

Espressioni regolari(C++11)

Operazioni atomicche(C++11)

Multithreading(C++11)

 

Discussione libreria di supporto

Threads Original: Threads The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
thread (C++11)
this_thread spazio dei nomi Original: this_thread namespace The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
get_id (C++11) yield (C++11)	sleep_for (C++11) sleep_until (C++11)
Mutua esclusione Original: Mutual exclusion The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
mutex (C++11) timed_mutex (C++11)	recursive_mutex (C++11) recursive_timed_mutex (C++11)
Blocco di gestione generico Original: Generic lock management The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
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)
Condizioni variabili Original: Condition variables The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
condition_variable (C++11)
condition_variable_any (C++11)
notify_all_at_thread_exit (C++11)
cv_status (C++11)
Futures Original: Futures The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
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::future

future::future

future::~future

future::operator=

future::share

Ottenere il risultato Original: Getting the result The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

future::get

Stato Original: State The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

future::valid

future::wait

future::wait_for

future::wait_until

 

Elemento definito nell'header <future>
template<class T >class future;	(1)	(dal C++11)
template<class T >class future<T&>;	(2)	(dal C++11)
template<>          class future<void>;	(3)	(dal C++11)

Il std::future modello di classe fornisce un meccanismo per accedere al risultato delle operazioni asincrone:

Original:

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

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• Un'operazione asincrona (creato tramite std::async, std::packaged_task o std::promise) in grado di fornire un oggetto std::future al creatore di tale operazione asincrona.

  Original:

  An asynchronous operation (created via std::async, std::packaged_task, or std::promise) can provide a std::future object to the creator of that asynchronous operation.

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• Il creatore dell'operazione asincrona può utilizzare una varietà di metodi per le query, aspettare, o estrarre un valore dal std::future. Questi metodi possono bloccare se l'operazione asincrona non ha ancora fornito un valore.

  Original:

  The creator of the asynchronous operation can then use a variety of methods to query, wait for, or extract a value from the std::future. These methods may block if the asynchronous operation has not yet provided a value.

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• Quando l'operazione asincrona è pronto per inviare un risultato al creatore, può farlo mediante la modifica dello stato condiviso (ad esempio std::promise::set_value) che è legata alla std::future del creatore.

  Original:

  When the asynchronous operation is ready to send a result to the creator, it can do so by modifying shared state (e.g. std::promise::set_value) that is linked to the creator's std::future.

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Si noti che i riferimenti std::future stato condiviso che non sia condivisa con altri oggetti di ritorno asincroni (a differenza std::shared_future).

Original:

Note that std::future references shared state that is not shared with any other asynchronous return objects (as opposed to std::shared_future).

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Membri funzioni

(costruttore)	costruisce l'oggetto futuro Original: constructs the future object The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (metodo pubblico)
(destructor)	distrugge l'oggetto futuro Original: destructs the future object The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (metodo pubblico)
operator=	sposta l'oggetto futuro Original: moves the future object The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (metodo pubblico)
share	restituisce un shared_future riferimento al risultato associato al *this Original: returns a shared_future referring to the result associated to *this The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (metodo pubblico)
Ottenere il risultato Original: Getting the result The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
get	restituisce il risultato Original: returns the result The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (metodo pubblico)
Stato Original: State The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
valid	Verifica se il futuro è stato condiviso con una promessa Original: checks if the future has shared state with a promise The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (metodo pubblico)
wait	attende il risultato diventi disponibile Original: waits for the result to become available The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (metodo pubblico)
wait_for	waits for the result, returns if it is not available for the specified timeout duration (metodo pubblico)
wait_until	aspetta il risultato, restituisce se non è disponibile fino punto di tempo specificato è stato raggiunto Original: waits for the result, returns if it is not available until specified time point has been reached The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (metodo pubblico)

Esempio

#include <iostream>#include <future>#include <thread>   int main(){// future from a packaged_taskstd::packaged_task<int()> task([](){return7;});// wrap the function std::future<int> f1 = task.get_future();// get a futurestd::thread(std::move(task)).detach();// launch on a thread   // future from an async() std::future<int> f2 =std::async(std::launch::async, [](){return8;});   // future from a promisestd::promise<int> p; std::future<int> f3 = p.get_future();std::thread([](std::promise<int>& p){ p.set_value(9);}, std::ref(p)).detach();   std::cout<<"Waiting..."; f1.wait(); f2.wait(); f3.wait();std::cout<<"Done!\nResults are: "<< f1.get()<<' '<< f2.get()<<' '<< f3.get()<<'\n';}

Output:

Waiting...Done! Results are: 7 8 9

Vedi anche

async (C++11)	esegue una funzione in modo asincrono (potenzialmente in un nuovo thread) e restituisce un std::future che conterrà il risultato Original: runs a function asynchronously (potentially in a new thread) and returns a std::future that will hold the result The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (funzione di modello)
shared_future (C++11)	attende un valore (eventualmente riferimento altri futuri) che è impostato in modo asincrono Original: waits for a value (possibly referenced by other futures) that is set asynchronously The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (classe template)