threadschedule::advanced::future_with_error_handler< T > Class Template Reference

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

#include <error_handler.hpp>

Public Member Functions
	future_with_error_handler (std::future< T > future)
	future_with_error_handler (future_with_error_handler const &)=delete
auto	operator= (future_with_error_handler const &) -> future_with_error_handler &=delete
	future_with_error_handler (future_with_error_handler &&)=default
auto	operator= (future_with_error_handler &&) -> future_with_error_handler &=default
auto	on_error (std::function< void(std::exception_ptr)> callback) -> future_with_error_handler &
	Attach an error callback.
template<typename Callback , std::enable_if_t<!std::is_same_v<::threadschedule::detail::remove_cvref_t< Callback >, std::function< void(std::exception_ptr)> >, int > = 0>
auto	on_error (Callback &&callback) -> future_with_error_handler &
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::advanced::future_with_error_handler< T >

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

future_with_error_handler<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 285 of file error_handler.hpp.

Constructor & Destructor Documentation

future_with_error_handler() [1/3]

template<typename T >

threadschedule::advanced::future_with_error_handler< T >::future_with_error_handler ( std::future< T >  future )

inlineexplicit

Definition at line 288 of file error_handler.hpp.

future_with_error_handler() [2/3]

template<typename T >

threadschedule::advanced::future_with_error_handler< T >::future_with_error_handler ( future_with_error_handler< T > const &  )

delete

future_with_error_handler() [3/3]

template<typename T >

threadschedule::advanced::future_with_error_handler< T >::future_with_error_handler ( future_with_error_handler< T > &&  )

default

Member Function Documentation

get()

template<typename T >

auto threadschedule::advanced::future_with_error_handler< 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. Exceptions from the callback are ignored so they cannot replace the original failure.

Returns

The stored value of type T (void when T is void).

Exceptions

Any	exception stored in the underlying std::future.

Definition at line 341 of file error_handler.hpp.

on_error() [1/2]

template<typename T >

template<typename Callback , std::enable_if_t<!std::is_same_v<::threadschedule::detail::remove_cvref_t< Callback >, std::function< void(std::exception_ptr)> >, int > = 0>

auto threadschedule::advanced::future_with_error_handler< T >::on_error ( Callback &&  callback ) -> future_with_error_handler&

inline

Definition at line 320 of file error_handler.hpp.

on_error() [2/2]

template<typename T >

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

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 309 of file error_handler.hpp.

operator=() [1/2]

template<typename T >

auto threadschedule::advanced::future_with_error_handler< T >::operator= ( future_with_error_handler< T > &&  ) -> future_with_error_handler &=default

default

operator=() [2/2]

template<typename T >

auto threadschedule::advanced::future_with_error_handler< T >::operator= ( future_with_error_handler< T > const &  ) -> future_with_error_handler &=delete

delete

valid()

template<typename T >

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

inline

Check whether the future refers to a shared state.

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

Definition at line 412 of file error_handler.hpp.

wait()

template<typename T >

void threadschedule::advanced::future_with_error_handler< T >::wait ( ) const

inline

Block until the result is ready.

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

Definition at line 373 of file error_handler.hpp.

wait_for()

template<typename T >

template<typename Rep , typename Period >

auto threadschedule::advanced::future_with_error_handler< 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 387 of file error_handler.hpp.

wait_until()

template<typename T >

template<typename Clock , typename duration >

auto threadschedule::advanced::future_with_error_handler< 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 401 of file error_handler.hpp.

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

• error_handler.hpp