2022-01-20 08:41:32 +01:00

98 lines
3.7 KiB
C++

/*
/~` _ _ _|_. _ _ |_ | _
\_,(_)| | | || ||_|(_||_)|(/_
https://github.com/Naios/continuable
v4.2.0
Copyright(c) 2015 - 2022 Denis Blank <denis.blank at outlook dot com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files(the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions :
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
**/
#ifndef CONTINUABLE_DETAIL_PROMISIFY_HPP_INCLUDED
#define CONTINUABLE_DETAIL_PROMISIFY_HPP_INCLUDED
#include <type_traits>
#include <continuable/continuable-base.hpp>
#include <continuable/continuable-primitives.hpp>
#include <continuable/detail/features.hpp>
#include <continuable/detail/utility/traits.hpp>
#include <continuable/detail/utility/util.hpp>
#if defined(CONTINUABLE_HAS_EXCEPTIONS)
#include <exception>
#endif // CONTINUABLE_HAS_EXCEPTIONS
namespace cti {
namespace detail {
namespace convert {
/// A resolver for promisifying asio and js style callbacks.
inline auto default_resolver() {
return [](auto&& promise, auto&& e, auto&&... args) {
static_assert(
std::is_convertible<std::decay_t<decltype(e)>, exception_t>::value,
"The given error type must be convertible to the error type used! "
"Specify a custom resolver in order to apply a conversion to the "
"used error type.");
if (e) {
promise.set_exception(std::forward<decltype(e)>(e));
} else {
promise.set_value(std::forward<decltype(args)>(args)...);
}
};
}
template <typename... Result>
struct promisify_helper {
template <typename Resolver, typename Callable, typename... Args>
static auto from(Resolver&& resolver, Callable&& callable, Args&&... args) {
return make_continuable<Result...>(
[resolver = std::forward<Resolver>(resolver),
args = traits::make_flat_tuple(std::forward<Callable>(callable),
std::forward<Args>(args)...)](
auto&& promise) mutable {
traits::unpack(
[promise = std::forward<decltype(promise)>(promise),
&resolver](auto&&... args) mutable {
// Call the resolver from with the promise and result
auto callback =
[resolver = std::move(resolver),
promise = std::move(promise)](auto&&... args) mutable {
resolver(std::move(promise),
std::forward<decltype(args)>(args)...);
};
// Invoke the callback taking function
util::invoke(std::forward<decltype(args)>(args)...,
std::move(callback));
},
std::move(args));
});
}
};
} // namespace convert
} // namespace detail
} // namespace cti
#endif // CONTINUABLE_DETAIL_PROMISIFY_HPP_INCLUDED