v1::scoped_task< T > Class Template Reference

#include <hikogui/scoped_task.hpp>

Data Structures
struct	promise_type

Public Types
using	value_type = T
using	return_value_type = std::variant<std::monostate, std::exception_ptr, value_type>
	The return value type.
using	return_value_ptr_type = std::shared_ptr<return_value_type>
using	const_return_value_ptr_type = std::shared_ptr<return_value_type const>
using	notifier_type = notifier<void(value_type)>
using	handle_type = std::coroutine_handle<promise_type>

Public Member Functions
	scoped_task (handle_type coroutine, const_return_value_ptr_type value_ptr) noexcept
	scoped_task (scoped_task const &)=delete
scoped_task &	operator= (scoped_task const &)=delete
	scoped_task (scoped_task &&other) noexcept
scoped_task &	operator= (scoped_task &&other) noexcept
bool	completed () const noexcept
	Check if the co-routine has completed.
	operator bool () const noexcept
	Check if the co-routine has completed.
value_type const &	value () const
	Get the return value returned from co_return.
value_type const &	operator* () const
	Get the return value returned from co_return.
notifier_type::token_type	subscribe (std::invocable< value_type > auto &&callback) noexcept
	Subscribe a callback for when the co-routine is completed.

Detailed Description

template<typename T = void>
class v1::scoped_task< T >

A scoped_task.

Like the hi::task instance this implements a asynchronous co-routine task.

If the scoped_task object is destroyed, the potentially non-completed co-routine will be destroyed as well. A scoped_task is a move-only object.

Template Parameters

T	The type returned by co_return.

Member Typedef Documentation

return_value_type

template<typename T = void>

using v1::scoped_task< T >::return_value_type = std::variant<std::monostate, std::exception_ptr, value_type>

The return value type.

This value is shared between the promise and the scoped_task. The variant has three different states:

• 0: co-routine has not completed.
• 1: co-routine caught an uncaught exception.
• 2: co-routine is completed with a value.

Member Function Documentation

completed()

template<typename T = void>

bool v1::scoped_task< T >::completed ( ) const

inlinenoexcept

Check if the co-routine has completed.

operator bool()

template<typename T = void>

v1::scoped_task< T >::operator bool ( ) const

inlineexplicitnoexcept

Check if the co-routine has completed.

operator*()

template<typename T = void>

value_type const & v1::scoped_task< T >::operator* ( ) const

inline

Get the return value returned from co_return.

Note

It is undefined behavior to call this function if the co-routine is incomplete.

Exceptions

The	exception thrown from the co-routine.

subscribe()

template<typename T = void>

notifier_type::token_type v1::scoped_task< T >::subscribe ( std::invocable< value_type > auto && callback )

inlinenoexcept

Subscribe a callback for when the co-routine is completed.

Parameters

callback

The callback to call when the co-routine executed co_return. If co_return has a non-void expression then the callback must accept the expression as an argument.

value()

template<typename T = void>

value_type const & v1::scoped_task< T >::value ( ) const

inline

Get the return value returned from co_return.

Note

It is undefined behavior to call this function if the co-routine is incomplete.

Exceptions

The	exception thrown from the co-routine.

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

• hikogui/src/hikogui/scoped_task.hpp