TFutureBase< ResultType > Class Template Reference

#include <Future.h>

Inheritance diagram for TFutureBase< ResultType >:

Public Types
using	MutableResultType = typename StateType::MutableResultType
using	ConstResultType = typename StateType::ConstResultType
using	RvalueResultType = typename StateType::RvalueResultType

Public Member Functions
ConstResultType	Get () const
ConstResultType	Get () const UE_LIFETIMEBOUND
bool	IsReady () const
bool	IsValid () const
void	Wait () const
bool	WaitFor (const FTimespan &Duration) const
bool	WaitUntil (const FDateTime &Time) const

Protected Types
using	StateType = TFutureState< ResultType >

Protected Member Functions
	TFutureBase ()=default
	TFutureBase (TSharedPtr< StateType > &&InState)
	TFutureBase (const TSharedPtr< StateType > &InState)
const TSharedPtr< StateType > &	GetState () const
template<typename Func >
auto	Then (Func Continuation)
template<typename Func >
auto	Next (Func Continuation)
void	Reset ()

Detailed Description

template<typename ResultType>
class TFutureBase< ResultType >

Abstract base template for futures and shared futures.

Member Typedef Documentation

ConstResultType

template<typename ResultType >

using TFutureBase< ResultType >::ConstResultType = typename StateType::ConstResultType

MutableResultType

template<typename ResultType >

using TFutureBase< ResultType >::MutableResultType = typename StateType::MutableResultType

RvalueResultType

template<typename ResultType >

using TFutureBase< ResultType >::RvalueResultType = typename StateType::RvalueResultType

StateType

template<typename ResultType >

using TFutureBase< ResultType >::StateType = TFutureState<ResultType>

protected

Constructor & Destructor Documentation

TFutureBase() [1/3]

template<typename ResultType >

TFutureBase< ResultType >::TFutureBase ( )

protecteddefault

Default constructor.

TFutureBase() [2/3]

template<typename ResultType >

TFutureBase< ResultType >::TFutureBase ( TSharedPtr< StateType > &&  InState )

inlineprotected

Creates and initializes a new instance.

Parameters

InState

The shared state to initialize with.

TFutureBase() [3/3]

template<typename ResultType >

TFutureBase< ResultType >::TFutureBase ( const TSharedPtr< StateType > &  InState )

inlineprotected

Member Function Documentation

Get() [1/2]

template<typename ResultType >

ConstResultType TFutureBase< ResultType >::Get ( ) const

inline

Gets the future's result.

Returns

The result as a const reference, or the same reference if the future holds a reference, or void if the future holds a void.

Note

Not equivalent to std::future::get(). The future remains valid.

Get() [2/2]

template<typename ResultType >

ConstResultType TFutureBase< ResultType >::Get ( ) const

inline

GetState()

template<typename ResultType >

const TSharedPtr< StateType > & TFutureBase< ResultType >::GetState ( ) const

inlineprotected

Gets the shared state object.

Returns

The shared state object.

IsReady()

template<typename ResultType >

bool TFutureBase< ResultType >::IsReady ( ) const

inline

Checks whether this future object has its value set.

Returns

true if this future has a shared state and the value has been set, false otherwise.

See also

IsValid

IsValid()

template<typename ResultType >

bool TFutureBase< ResultType >::IsValid ( ) const

inline

Checks whether this future object has a valid state.

Returns

true if the state is valid, false otherwise.

See also

IsReady

Next()

template<typename ResultType >

template<typename Func >

auto TFutureBase< ResultType >::Next ( Func  Continuation )

protected

Convenience wrapper for Then that set a completion callback that will be called once the future completes or immediately if already completed

Parameters

Continuation

a continuation taking an argument of type ResultType

Returns

nothing at the moment but could return another future to allow future chaining

Reset()

template<typename ResultType >

void TFutureBase< ResultType >::Reset ( )

inlineprotected

Reset the future. Resetting a future removes any continuation from its shared state and invalidates it. Useful for discarding yet to be completed future cleanly.

Then()

template<typename ResultType >

template<typename Func >

auto TFutureBase< ResultType >::Then ( Func  Continuation )

protected

Set a completion callback that will be called once the future completes or immediately if already completed

Parameters

Continuation

a continuation taking an argument of type TFuture<ResultType>

Returns

nothing at the moment but could return another future to allow future chaining

Wait()

template<typename ResultType >

void TFutureBase< ResultType >::Wait ( ) const

inline

Blocks the calling thread until the future result is available.

Note that this method may block forever if the result is never set. Use the WaitFor or WaitUntil methods to specify a maximum timeout for the wait.

See also

WaitFor, WaitUntil

WaitFor()

template<typename ResultType >

bool TFutureBase< ResultType >::WaitFor ( const FTimespan &  Duration ) const

inline

Blocks the calling thread until the future result is available or the specified duration is exceeded.

Parameters

Duration

The maximum time span to wait for the future result.

Returns

true if the result is available, false otherwise.

See also

Wait, WaitUntil

WaitUntil()

template<typename ResultType >

bool TFutureBase< ResultType >::WaitUntil ( const FDateTime &  Time ) const

inline

Blocks the calling thread until the future result is available or the specified time is hit.

Parameters

Time	The time until to wait for the future result (in UTC).

Returns

true if the result is available, false otherwise.

See also

Wait, WaitUntil

---

The documentation for this class was generated from the following file:

• Engine/Source/Runtime/Core/Public/Async/Future.h