kcenon::container::async::task< T > Class Template Reference

Forward declaration of task. More...

#include <task.h>

Collaboration diagram for kcenon::container::async::task< T >:

Classes
struct	awaiter
	Awaitable interface. More...

Public Types
using	promise_type = detail::promise_type<T>
using	handle_type = std::coroutine_handle<promise_type>

Public Member Functions
	task () noexcept
	Default constructor - creates empty task.
	task (handle_type handle) noexcept
	Construct from coroutine handle.
	task (task &&other) noexcept
	Move constructor.
task &	operator= (task &&other) noexcept
	Move assignment operator.
	~task ()
	Destructor - destroys the coroutine if owned.
	task (const task &)=delete
task &	operator= (const task &)=delete
bool	valid () const noexcept
	Check if task is valid (has a coroutine)
	operator bool () const noexcept
	Check if task is valid (has a coroutine)
bool	done () const noexcept
	Check if the coroutine is done.
decltype(auto)	get () &
	Get the result (blocking, for testing)
decltype(auto)	get () &&
	Get the result (rvalue, blocking, for testing)
awaiter	operator co_await () noexcept
	Get awaiter for co_await.
void	resume () const
	Resume the coroutine (for manual execution)

Private Attributes
handle_type	handle_

Detailed Description

template<typename T>
class kcenon::container::async::task< T >

Forward declaration of task.

Coroutine task type for async operations.

This is a lazy coroutine type that starts executing when awaited. It supports:

• Value-returning coroutines (task<T>)
• Void-returning coroutines (task<void>)
• Exception propagation
• Proper RAII resource management

Properties:

• Move-only (non-copyable)
• Lazy execution (starts when awaited)
• Symmetric transfer for efficient chaining

Template Parameters

T	The return type of the coroutine

Examples

async_coroutine_example.cpp.

Definition at line 208 of file task.h.

Member Typedef Documentation

handle_type

template<typename T >

using kcenon::container::async::task< T >::handle_type = std::coroutine_handle<promise_type>

Definition at line 212 of file task.h.

promise_type

template<typename T >

using kcenon::container::async::task< T >::promise_type = detail::promise_type<T>

Definition at line 211 of file task.h.

Constructor & Destructor Documentation

task() [1/4]

template<typename T >

kcenon::container::async::task< T >::task ( )

inlinenoexcept

Default constructor - creates empty task.

Definition at line 217 of file task.h.

: handle_(nullptr) {}

task() [2/4]

template<typename T >

kcenon::container::async::task< T >::task ( handle_type handle )

inlineexplicitnoexcept

Construct from coroutine handle.

Definition at line 222 of file task.h.

: handle_(handle) {}

task() [3/4]

template<typename T >

kcenon::container::async::task< T >::task ( task< T > && other )

inlinenoexcept

Move constructor.

Definition at line 227 of file task.h.

: handle_(std::exchange(other.handle_, nullptr)) {}

~task()

template<typename T >

kcenon::container::async::task< T >::~task ( )

inline

Destructor - destroys the coroutine if owned.

Definition at line 248 of file task.h.

        {
            if (handle_)
            {
                handle_.destroy();
            }
        }

References kcenon::container::async::task< T >::handle_.

task() [4/4]

template<typename T >

kcenon::container::async::task< T >::task ( const task< T > & )

delete

Member Function Documentation

done()

template<typename T >

bool kcenon::container::async::task< T >::done ( ) const

inlinenodiscardnoexcept

Check if the coroutine is done.

Uses atomic flag for thread-safe completion checking. This avoids data races when polling from a different thread than the one executing the coroutine.

Definition at line 283 of file task.h.

        {
            return handle_ && handle_.promise().completed_.load(std::memory_order_acquire);
        }

References kcenon::container::async::task< T >::handle_.

get() [1/2]

template<typename T >

decltype(auto) kcenon::container::async::task< T >::get ( ) &

inlinenodiscard

Get the result (blocking, for testing)

Warning

This assumes the coroutine has already completed

Definition at line 293 of file task.h.

        {
            return handle_.promise().result();
        }

References kcenon::container::async::task< T >::handle_.

get() [2/2]

template<typename T >

decltype(auto) kcenon::container::async::task< T >::get ( ) &&

inlinenodiscard

Get the result (rvalue, blocking, for testing)

Definition at line 301 of file task.h.

        {
            return std::move(handle_.promise()).result();
        }

References kcenon::container::async::task< T >::handle_.

operator bool()

template<typename T >

kcenon::container::async::task< T >::operator bool ( ) const

inlineexplicitnodiscardnoexcept

Check if task is valid (has a coroutine)

Definition at line 271 of file task.h.

        {
            return valid();
        }

References kcenon::container::async::task< T >::valid().

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operator co_await()

template<typename T >

awaiter kcenon::container::async::task< T >::operator co_await ( )

inlinenodiscardnoexcept

Get awaiter for co_await.

Definition at line 343 of file task.h.

        {
            return awaiter{handle_};
        }

References kcenon::container::async::task< T >::handle_.

operator=() [1/2]

template<typename T >

task & kcenon::container::async::task< T >::operator= ( const task< T > & )

delete

operator=() [2/2]

template<typename T >

task & kcenon::container::async::task< T >::operator= ( task< T > && other )

inlinenoexcept

Move assignment operator.

Definition at line 232 of file task.h.

        {
            if (this != &other)
            {
                if (handle_)
                {
                    handle_.destroy();
                }
                handle_ = std::exchange(other.handle_, nullptr);
            }
            return *this;
        }

References kcenon::container::async::task< T >::handle_.

resume()

template<typename T >

void kcenon::container::async::task< T >::resume ( ) const

inline

Resume the coroutine (for manual execution)

Definition at line 351 of file task.h.

        {
            if (handle_ && !handle_.done())
            {
                handle_.resume();
            }
        }

References kcenon::container::async::task< T >::handle_.

valid()

template<typename T >

bool kcenon::container::async::task< T >::valid ( ) const

inlinenodiscardnoexcept

Check if task is valid (has a coroutine)

Definition at line 263 of file task.h.

        {
            return handle_ != nullptr;
        }

References kcenon::container::async::task< T >::handle_.

Referenced by kcenon::container::async::task< T >::operator bool().

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Member Data Documentation

handle_

template<typename T >

handle_type kcenon::container::async::task< T >::handle_

private

Definition at line 360 of file task.h.

Referenced by kcenon::container::async::task< T >::done(), kcenon::container::async::task< T >::get(), kcenon::container::async::task< T >::get(), kcenon::container::async::task< T >::operator co_await(), kcenon::container::async::task< T >::operator=(), kcenon::container::async::task< T >::resume(), kcenon::container::async::task< T >::valid(), and kcenon::container::async::task< T >::~task().

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

• internal/async/task.h