Template Class MultiFuture

Class Documentation

template<typename T>
class MultiFuture

Aggregate container of multiple futures.

Public Functions

MultiFuture(std::initializer_list<Future<T>>)

Create a MultiFuture with a collection of futures.

Throws:

  • std::logic_error – If any of the futures belongs to a different pool from the others

  • std::length_error – If the list of futures is empty

explicit MultiFuture(std::vector<Future<T>>&&)

Create a MultiFuture with a collection of futures.

Throws:

  • std::logic_error – If any of the futures belongs to a different pool from the others

  • std::length_error – If the list of futures is empty

std::size_t size() const noexcept

Get the number of collected futures.

Returns:

Future count

void await()

Block until all futures have completed execution.

Status checkStatus() const noexcept

Get the overall status of the collection.

The status progresses as follows: starting at Pending (then Scheduled once scheduled to run), once any future starts executing the status is set to Executing, then Complete once all futures have completed.

The status will be set to Failed if any future fails. The Yielding status is never returned.

Returns:

The overall status

template<typename F, typename ...ExArgs, typename R = std::invoke_result_t<F&&, std::vector<T>, ExArgs&&...>>
Future<R> then(F &&func, ExArgs&&... exargs)

Schedule a tracked task for execution after these futures.

Template Parameters:

  • F – Function type

  • ExArgs – Arguments to the function

  • R – Function return type

Parameters:

  • func – The function to invoke

  • exargs – Extra arguments to pass to the function

Throws:

  • std::logic_error – If any of the futures fail

  • std::bad_weak_ptr – If the pool to which the futures belong no longer exists

template<typename F, typename ...ExArgs>
void thenDetached(F &&func, ExArgs&&... exargs)

Schedule a tracked task for execution after these futures with no result.

Template Parameters:

  • F – Function type

  • ExArgs – Extra arguments to the function

Parameters:

  • func – The function to invoke

  • exargs – Extra arguments to pass to the function

Throws:

  • std::logic_error – If any of the futures fail

  • std::bad_weak_ptr – If the pool to which the futures belong no longer exists

template<typename F, typename ...ExArgs, typename R = std::invoke_result_t<F&&, T, ExArgs&&...>>
MultiFuture<R> thenBatch(F &&func, ExArgs&&... exargs)

Schedule a tracked batch job based on a container for execution after these futures.

This function does not exist in the void specialization of this type

Attention

If some futures fail but others do not and a batch continuation has been scheduled, the successful jobs will run their continuations and the failed ones will not. Keep this in mind.

Template Parameters:

  • F – Function type

  • ExArgs – Extra arguments to the function

  • R – Function return type

Parameters:

  • func – The function to invoke

  • exargs – Extra arguments to pass to the function

Throws:

  • std::logic_error – If any of the futures fail

  • std::bad_weak_ptr – If the pool to which the futures belong no longer exists

template<typename F, typename ...ExArgs>
void thenBatchDetached(F &&func, ExArgs&&... exargs)

Schedule a batch job based on a container for execution after these futures with no result.

This function does not exist in the void specialization of this type

Attention

If some futures fail but others do not and a batch continuation has been scheduled, the successful jobs will run their continuations and the failed ones will not. Keep this in mind.

Template Parameters:

  • F – Function type

  • ExArgs – Extra arguments to the function

Parameters:

  • func – The function to invoke

  • exargs – Extra arguments to pass to the function

Throws:

  • std::logic_error – If any of the futures fail

  • std::bad_weak_ptr – If the pool to which the futures belong no longer exists

std::vector<T> results()

Get the results of the futures, blocking if not complete.

This function does not exist in the void specialization of this type

Throws:

std::runtime_error – If any of the futures failed

Returns:

A list of results corresponding to the order of futures as placed in the constructor