Enables actors to delay a response message by capturing the context of a request message. More...

#include <response_promise.hpp>

Public Types
using	forwarding_stack = std::vector< strong_actor_ptr >

Public Member Functions
	response_promise (response_promise &&)=default

	response_promise (const response_promise &)=default

response_promise &	operator= (response_promise &&)=default

response_promise &	operator= (const response_promise &)=default

bool	async () const noexcept
	Returns whether this response promise replies to an asynchronous message.

bool	pending () const noexcept
	Queries whether this promise is a valid promise that is not satisfied yet.

strong_actor_ptr	source () const noexcept
	Returns the source of the corresponding request.

forwarding_stack	stages () const
	Returns the remaining stages for the corresponding request.

strong_actor_ptr	next () const noexcept
	Returns the actor that will receive the response, i.e., `stages().front()` if `!stages().empty()` or `source()` otherwise.

message_id	id () const noexcept
	Returns the message ID of the corresponding request.

void	deliver (message msg)
	Satisfies the promise by sending the given message.

void	deliver (error x)
	Satisfies the promise by sending an error message.

void	deliver ()
	Satisfies the promise by sending an empty message.

void	deliver (unit_t)
	Satisfies the promise by sending an empty message.

template<class... Ts>
void	deliver (Ts... xs)
	Satisfies the promise by sending `make_message(xs...)`.

template<class T >
void	deliver (expected< T > x)
	Satisfies the promise by sending the content of `x`, i.e., either a value of type `T` or an error.

template<message_priority P = message_priority::normal, class Handle = actor, class... Ts>
delegated_response_type_t< typename Handle::signatures, detail::implicit_conversions_t< std::decay_t< Ts > >... >	delegate (const Handle &dest, Ts &&... xs)
	Satisfies the promise by delegating to another actor.

Friends
class	local_actor

class	stream_manager

template<class... >
class	typed_response_promise

Detailed Description

Enables actors to delay a response message by capturing the context of a request message.

This is particularly useful when an actor needs to communicate to other actors in order to fulfill a request for a client.

Member Function Documentation

◆ delegate()

template<message_priority P = message_priority::normal, class Handle = actor, class... Ts>

delegated_response_type_t< typename Handle::signatures, detail::implicit_conversions_t< std::decay_t< Ts > >... > caf::response_promise::delegate	(	const Handle &	dest,
		Ts &&...	xs
	)

Satisfies the promise by delegating to another actor.

Postcondition: pending() == false

◆ deliver() [1/6]

void caf::response_promise::deliver ( )

Satisfies the promise by sending an empty message.

Note: Sends no message if the request message was asynchronous, i.e., if async() == true.

Postcondition: pending() == false

◆ deliver() [2/6]

void caf::response_promise::deliver ( error x )

Satisfies the promise by sending an error message.

Postcondition: pending() == false

◆ deliver() [3/6]

template<class T >

void caf::response_promise::deliver ( expected< T > x )

Satisfies the promise by sending the content of x, i.e., either a value of type T or an error.

Postcondition: pending() == false

◆ deliver() [4/6]

void caf::response_promise::deliver ( message msg )

Satisfies the promise by sending the given message.

Note: Drops empty messages silently when responding to an asynchronous request message, i.e., if async() == true.

Postcondition: pending() == false

◆ deliver() [5/6]

template<class... Ts>

void caf::response_promise::deliver ( Ts... xs )

Satisfies the promise by sending make_message(xs...).

Postcondition: pending() == false

◆ deliver() [6/6]

void caf::response_promise::deliver ( unit_t )