await.hpp

Go to the documentation of this file.

#pragma once
 
#include <yaclib/async/future.hpp>
#include <yaclib/coro/coro.hpp>
#include <yaclib/coro/detail/await_awaiter.hpp>
#include <yaclib/util/type_traits.hpp>
 
namespace yaclib {
 
/**
 * TODO(mkornaukhov03) Add doxygen docs
 */
template <typename V, typename E>
YACLIB_INLINE auto Await(Task<V, E>& task) noexcept {
  YACLIB_ASSERT(task.Valid());
  return detail::TransferAwaiter{UpCast<detail::BaseCore>(*task.GetCore())};
}
 
/**
 * TODO(mkornaukhov03) Add doxygen docs
 */
template <typename... V, typename... E>
YACLIB_INLINE auto Await(FutureBase<V, E>&... fs) noexcept {
  YACLIB_ASSERT(... && fs.Valid());
  return detail::AwaitAwaiter<sizeof...(fs) == 1>{UpCast<detail::BaseCore>(*fs.GetCore())...};
}
 
/**
 * TODO(mkornaukhov03) Add doxygen docs
 */
template <typename Iterator>
YACLIB_INLINE auto Await(Iterator begin, std::size_t count) noexcept
  -> std::enable_if_t<!is_future_base_v<Iterator>, detail::AwaitAwaiter<false>> {
  return detail::AwaitAwaiter<false>{begin, count};
}
 
/**
 * TODO(mkornaukhov03) Add doxygen docs
 */
template <typename Iterator>
YACLIB_INLINE auto Await(Iterator begin, Iterator end) noexcept
  -> std::enable_if_t<!is_future_base_v<Iterator>, detail::AwaitAwaiter<false>> {
  // We don't use std::distance because we want to alert the user to the fact that it can be expensive.
  // Maybe the user has the size of the range, otherwise it is suggested to call Await(begin, distance(begin, end))
  return Await(begin, static_cast<std::size_t>(end - begin));
}
 
template <typename V, typename E>
YACLIB_INLINE auto operator co_await(FutureBase<V, E>&& future) noexcept {
  YACLIB_ASSERT(future.Valid());
  return detail::AwaitSingleAwaiter{std::move(future.GetCore())};
}
 
template <typename V, typename E>
YACLIB_INLINE auto operator co_await(Task<V, E>&& task) noexcept {
  YACLIB_ASSERT(task.Valid());
  return detail::TransferSingleAwaiter{std::move(task.GetCore())};
}
 
}  // namespace yaclib