uvco::Promise< void > Class Reference

#include <promise.h>

Collaboration diagram for uvco::Promise< void >:

Classes
struct	PromiseAwaiter_
	Handles the actual suspension and resumption. More...

Public Types
using	promise_type = Coroutine<void>

Public Member Functions
	Promise (Promise< void > &&other) noexcept
	Promise ready to be awaited or fulfilled.
Promise &	operator= (const Promise< void > &other)=delete
Promise &	operator= (Promise< void > &&other) noexcept
	Promise (const Promise< void > &other)=delete
	~Promise ()
PromiseAwaiter_	operator co_await () const
bool	ready () const
	Returns whether the promise has already been fulfilled.
void	unwrap ()

Private Types
using	PromiseCore_ = PromiseCore<void>

Private Member Functions
	Promise (PromiseCore_ &core)
PromiseCore< void > *	core ()

Private Attributes
PromiseCore< void > *	core_

Friends
class	Coroutine< void >
template<typename... Ts>
class	SelectSet
class	Coroutine

Detailed Description

A void promise works slightly differently than a Promise<T> in that it doesn't return a value. However, aside from return_void() being implemented instead of return_value(), the mechanics are identical.

NOTE: for a transition period, Promise<void> is more efficient than Promise<T>: it does not allocate a separate PromiseCore. Instead, the PromiseCore<void> is placed in the Coroutine<void> frame, which itself is allocated anyway.

Member Typedef Documentation

promise_type

using uvco::Promise< void >::promise_type = Coroutine<void>

Part of the coroutine protocol: Promise<void> is both return type and promise type.

PromiseCore_

using uvco::Promise< void >::PromiseCore_ = PromiseCore<void>

private

Constructor & Destructor Documentation

Promise() [1/3]

uvco::Promise< void >::Promise ( Promise< void > && other )

noexcept

Promise ready to be awaited or fulfilled.

                                                     : core_{other.core_} {
  other.core_ = nullptr;
}

Promise() [2/3]

uvco::Promise< void >::Promise ( const Promise< void > & other )

delete

~Promise()

uvco::Promise< void >::~Promise

(

)

                        {
  if (core_ != nullptr) {
    core_->destroyCoroutine();
  }
}

Promise() [3/3]

uvco::Promise< void >::Promise ( PromiseCore_ & core )

explicitprivate

: core_{&core} {}

Member Function Documentation

core()

PromiseCore< void > * uvco::Promise< void >::core ( )

inlineprivate

                            {
    BOOST_ASSERT(core_ != nullptr);
    return core_;
  }

operator co_await()

Promise< void >::PromiseAwaiter_ uvco::Promise< void >::operator co_await

(

)

const

Returns an awaiter object for the promise, handling actual suspension and resumption.

                                                                    {
  return PromiseAwaiter_{*core_};
}

operator=() [1/2]

Promise & uvco::Promise< void >::operator= ( const Promise< void > & other )

delete

operator=() [2/2]

Promise< void > & uvco::Promise< void >::operator= ( Promise< void > && other )

noexcept

                                                                      {
  if (this == &other) {
    return *this;
  }
  if (core_ != nullptr) {
    core_->destroyCoroutine();
  }
  core_ = other.core_;
  other.core_ = nullptr;
  return *this;
}

ready()

bool uvco::Promise< void >::ready ( ) const

nodiscard

Returns whether the promise has already been fulfilled.

{ return core_->ready_; }

unwrap()

void uvco::Promise< void >::unwrap

(

)

                           {
  if (ready()) {
    if (core_->exception_) {
      std::rethrow_exception(core_->exception_.value());
    }
  } else {
    throw UvcoException(UV_EAGAIN, "unwrap called on unfulfilled promise");
  }
}

Friends And Related Symbol Documentation

Coroutine

friend class Coroutine

friend

Coroutine< void >

friend class Coroutine< void >

friend

SelectSet

template<typename... Ts>

friend class SelectSet

friend

Member Data Documentation

core_

PromiseCore<void>* uvco::Promise< void >::core_

private

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

• uvco/promise/promise.h
• uvco/promise/promise.cc