dpp::moveable_promise< T > Class Template Reference

Generic promise class, represents the owning potion of an asynchronous value. More...

#include <awaitable.h>

Public Member Functions
template<bool Notify = true, typename... Args> requires (std::constructible_from<T, Args...>)
void	emplace_value (Args &&... args)
	Construct the result in place by forwarding the arguments, and by default resume any awaiter. More...
template<bool Notify = true, typename U = T> requires (std::convertible_to<U&&, T>)
void	set_value (U &&v)
	Construct the result by forwarding reference, and resume any awaiter. More...
template<bool Notify = true> requires (std::is_void_v<T>)
void	set_value ()
	Construct a void result, and resume any awaiter. More...
template<bool Notify = true>
void	set_exception (std::exception_ptr ptr)
void	notify_awaiter ()
	Notify a currently awaiting coroutine that the result is ready. More...
awaitable< T >	get_awaitable ()
	Get an awaitable object for this promise. More...

Detailed Description

template<typename T>
class dpp::moveable_promise< T >

Generic promise class, represents the owning potion of an asynchronous value.

This class is roughly equivalent to std::promise, with the crucial distinction that the promise IS the shared state. As such, the promise needs to be kept alive for the entire time a value can be retrieved.

The difference between basic_promise and this object is that this one is moveable as it wraps an underlying basic_promise in a std::unique_ptr.

See also

awaitable

Member Function Documentation

emplace_value()

template<typename T >

template<bool Notify = true, typename... Args>
requires (std::constructible_from<T, Args...>)

void dpp::moveable_promise< T >::emplace_value ( Args &&...  args )

inline

Construct the result in place by forwarding the arguments, and by default resume any awaiter.

Template Parameters

Notify

Whether to resume any awaiter or not.

Exceptions

dpp::logic_exception

if the promise is not empty.

get_awaitable()

template<typename T >

awaitable< T > dpp::moveable_promise< T >::get_awaitable ( )

inline

Get an awaitable object for this promise.

Exceptions

dpp::logic_exception

if get_awaitable has already been called on this object.

Returns

awaitable<T> An object that can be co_await-ed to retrieve the value of this promise.

notify_awaiter()

template<typename T >

void dpp::moveable_promise< T >::notify_awaiter ( )

inline

Notify a currently awaiting coroutine that the result is ready.

Note

This may resume the coroutine on the current thread.

Exceptions

?	Any exception thrown by the coroutine if resumed will propagate

set_exception()

template<typename T >

template<bool Notify = true>

void dpp::moveable_promise< T >::set_exception ( std::exception_ptr  ptr )

inline

set_value() [1/2]

template<typename T >

template<bool Notify = true>
requires (std::is_void_v<T>)

void dpp::moveable_promise< T >::set_value ( )

inline

Construct a void result, and resume any awaiter.

Template Parameters

Notify

Whether to resume any awaiter or not.

Exceptions

dpp::logic_exception

if the promise is not empty.

set_value() [2/2]

template<typename T >

template<bool Notify = true, typename U = T>
requires (std::convertible_to<U&&, T>)

void dpp::moveable_promise< T >::set_value ( U &&  v )

inline

Construct the result by forwarding reference, and resume any awaiter.

Template Parameters

Notify

Whether to resume any awaiter or not.

Exceptions

dpp::logic_exception

if the promise is not empty.