threadschedule::FutureWithErrorHandler< T > Class Template Reference

A move-only future wrapper that supports an error callback. More...

#include <error_handler.hpp>

Inheritance diagram for threadschedule::FutureWithErrorHandler< T >:

Public Member Functions
	FutureWithErrorHandler (std::future< T > future)
	FutureWithErrorHandler (FutureWithErrorHandler const &)=delete
auto	operator= (FutureWithErrorHandler const &) -> FutureWithErrorHandler &=delete
	FutureWithErrorHandler (FutureWithErrorHandler &&)=default
auto	operator= (FutureWithErrorHandler &&) -> FutureWithErrorHandler &=default
auto	on_error (std::function< void(std::exception_ptr)> callback) -> FutureWithErrorHandler &
	Attach an error callback.
auto	get () -> T
	Retrieve the result, invoking the error callback on failure.
void	wait () const
	Block until the result is ready.
template<typename Rep, typename Period>
auto	wait_for (std::chrono::duration< Rep, Period > const &timeout_duration) const
	Block until the result is ready or the timeout elapses.
template<typename Clock, typename Duration>
auto	wait_until (std::chrono::time_point< Clock, Duration > const &timeout_time) const
	Block until the result is ready or the given time point is reached.
auto	valid () const -> bool
	Check whether the future refers to a shared state.

Detailed Description

template<typename T>
class threadschedule::FutureWithErrorHandler< T >

A move-only future wrapper that supports an error callback.

FutureWithErrorHandler<T> wraps a std::future<T> and adds an optional error callback that fires when get() encounters an exception.

Template Parameters

T	The value type of the underlying future.

Move semantics

Like std::future, this type is move-only (copy construction and copy assignment are deleted).

Error callback behaviour

• Attach a callback with on_error(). At most one callback is supported; a subsequent call to on_error() replaces the previous callback.
• The callback is invoked before the exception is re-thrown from get().
• wait(), wait_for(), and wait_until() do not trigger the error callback.
• valid() delegates directly to the underlying std::future::valid().

Definition at line 294 of file error_handler.hpp.

Constructor & Destructor Documentation

FutureWithErrorHandler()

template<typename T>

threadschedule::FutureWithErrorHandler< T >::FutureWithErrorHandler ( std::future< T > future )

inlineexplicit

Definition at line 297 of file error_handler.hpp.

Member Function Documentation

get()

template<typename T>

auto threadschedule::FutureWithErrorHandler< T >::get ( ) -> T

inline

Retrieve the result, invoking the error callback on failure.

If the underlying future holds an exception, the error callback (if any) is called before the exception is re-thrown to the caller.

Returns

The stored value of type T.

Exceptions

Any	exception stored in the underlying std::future.

Definition at line 333 of file error_handler.hpp.

on_error()

template<typename T>

auto threadschedule::FutureWithErrorHandler< T >::on_error ( std::function< void(std::exception_ptr)> callback ) -> FutureWithErrorHandler&

inline

Attach an error callback.

The callback will be invoked with the current std::exception_ptr if get() encounters an exception. Only one callback is stored; calling on_error() again replaces the previous callback.

Parameters

callback

Callable invoked with the exception pointer on failure.

Returns

Reference to *this, allowing fluent chaining.

Definition at line 317 of file error_handler.hpp.

valid()

template<typename T>

auto threadschedule::FutureWithErrorHandler< T >::valid ( ) const -> bool

inlinenodiscard

Check whether the future refers to a shared state.

Delegates directly to std::future::valid().

Definition at line 390 of file error_handler.hpp.

wait()

template<typename T>

void threadschedule::FutureWithErrorHandler< T >::wait ( ) const

inline

Block until the result is ready.

Does not trigger the error callback regardless of the stored state.

Definition at line 354 of file error_handler.hpp.

wait_for()

template<typename T>

template<typename Rep, typename Period>

auto threadschedule::FutureWithErrorHandler< T >::wait_for ( std::chrono::duration< Rep, Period > const & timeout_duration ) const

inline

Block until the result is ready or the timeout elapses.

Does not trigger the error callback.

Returns

The std::future_status indicating whether the result is ready.

Definition at line 367 of file error_handler.hpp.

wait_until()

template<typename T>

template<typename Clock, typename Duration>

auto threadschedule::FutureWithErrorHandler< T >::wait_until ( std::chrono::time_point< Clock, Duration > const & timeout_time ) const

inline

Block until the result is ready or the given time point is reached.

Does not trigger the error callback.

Returns

The std::future_status indicating whether the result is ready.

Definition at line 380 of file error_handler.hpp.

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

• error_handler.hpp