dpp::detail::job::promise< Args > Struct Template Reference

Coroutine promise type for a job. More...

#include <job.h>

Public Member Functions
std_coroutine::suspend_never	final_suspend () const noexcept
std_coroutine::suspend_never	initial_suspend () const noexcept
dpp::job	get_return_object () const noexcept
	Function called to get the job object. More...
void	unhandled_exception () const
	Function called when an exception is thrown and not caught. More...
void	return_void () const noexcept
	Function called when the job returns. Does nothing. More...
template<typename T >
T	await_transform (T &&expr) const noexcept
	Function that will wrap every co_await inside of the job. More...

Detailed Description

template<typename... Args>
struct dpp::detail::job::promise< Args >

Coroutine promise type for a job.

Member Function Documentation

await_transform()

template<typename... Args>

template<typename T >

T dpp::detail::job::promise< Args >::await_transform ( T &&  expr ) const

inlinenoexcept

Function that will wrap every co_await inside of the job.

job is extremely efficient as a coroutine but this comes with drawbacks : It cannot be co_awaited, which means the second it co_awaits something, the program jumps back to the calling function, which continues executing. At this point, if the function returns, every object declared in the function including its parameters are destroyed, which causes dangling references. This is exactly the same problem as references in lambdas : https://dpp.dev/lambdas-and-locals.html.

If you must pass a reference, pass it as a pointer or with std::ref, but you must fully understand the reason behind this warning, and what to avoid. If you prefer a safer type, use coroutine for synchronous execution, or task for parallel tasks, and co_await them.

final_suspend()

template<typename... Args>

std_coroutine::suspend_never dpp::detail::job::promise< Args >::final_suspend ( ) const

inlinenoexcept

get_return_object()

template<typename... Args>

dpp::job dpp::detail::job::promise< Args >::get_return_object ( ) const

inlinenoexcept

Function called to get the job object.

Returns

job

initial_suspend()

template<typename... Args>

std_coroutine::suspend_never dpp::detail::job::promise< Args >::initial_suspend ( ) const

inlinenoexcept

return_void()

template<typename... Args>

void dpp::detail::job::promise< Args >::return_void ( ) const

inlinenoexcept

Function called when the job returns. Does nothing.

unhandled_exception()

template<typename... Args>

void dpp::detail::job::promise< Args >::unhandled_exception ( ) const

inline

Function called when an exception is thrown and not caught.

Exceptions

Immediately

rethrows the exception to the caller / resumer