continuable/fluent/Continuable.h
2015-06-11 17:52:19 +02:00

152 lines
4.2 KiB
C++

/*
* Copyright (C) 2015 Naios <naios-dev@live.de>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _CONTINUABLE_H_
#define _CONTINUABLE_H_
#include "Callback.h"
namespace detail
{
} // detail
template <typename... Args>
struct ContinuableState;
template <typename... Args>
struct ContinuableState<Args...>
{
};
template <typename _CTy, typename _State = ContinuableState<>>
class Continuable;
template <typename... _ATy, typename _State>
class Continuable<std::function<void(_ATy...)>, _State>
{
public:
typedef std::function<void(Callback<_ATy...>&&)> ForwardFunction;
private:
// Functional which expects a callback that is inserted from the Continuable
// to chain everything together
ForwardFunction _callback_insert;
bool _released;
void Dispatch()
{
}
public:
/// Deleted copy construct
template <typename _RCTy, typename _RState>
explicit Continuable(Continuable<_RCTy, _RState> const&) = delete;
/// Move construct
template <typename _RCTy, typename _RState>
explicit Continuable(Continuable<_RCTy, _RState>&& right)
: _released(right._released)
{
right._released = true;
}
// Construct through a ForwardFunction
template<typename _FTy>
Continuable(_FTy&& callback_insert)
: _callback_insert(std::forward<_FTy>(callback_insert)), _released(false) { }
/// Destructor which calls the dispatch chain if needed.
~Continuable()
{
if (!_released)
{
_released = true;
Dispatch();
}
}
/// Deleted copy assign
template <typename _RCTy, typename _RState>
Continuable& operator= (Continuable<_RCTy, _RState> const&) = delete;
/// Move construct assign
template <typename _RCTy, typename _RState>
Continuable& operator= (Continuable<_RCTy, _RState>&& right)
{
_released = right._released;
right._released = true;
return *this;
}
// TODO Accept only correct callbacks
template <typename _CTy>
Continuable<Callback<_ATy...>> then(_CTy&&)
{
// TODO Transmute the returned callback here.
return Continuable<Callback<_ATy...>>(std::move(*this));
}
/// Invalidates the Continuable
Continuable& invalidate()
{
_released = true;
return *this;
}
};
namespace detail
{
template <typename _FTy, typename _RTy, typename... _ATy>
struct ContinuableFactory;
template <typename _FTy, typename _RTy, typename... _ATy>
struct ContinuableFactory<_FTy, _RTy, ::fu::identity<std::function<void(_ATy...)>&&>>
{
static auto CreateFrom(_FTy&& functional)
-> Continuable<Callback<_ATy...>>
{
return Continuable<Callback<_ATy...>>(
typename Continuable<Callback<_ATy...>>::ForwardFunction(std::forward<_FTy>(functional)));
}
};
template <typename _FTy>
using continuable_factory_t = ContinuableFactory<
_FTy, ::fu::return_type_of_t<_FTy>, ::fu::argument_type_of_t<_FTy>>;
} // detail
/// Wraps a functional object which expects a r-value callback as argument into a continuable.
/// The callable is invoked when the continuable shall continue.
/// For example:
/// make_continuable([](Callback<int>&& callback)
/// {
/// /* Continue here */
/// callback(5);
/// });
template <typename _FTy>
inline auto make_continuable(_FTy&& functional)
-> decltype(detail::continuable_factory_t<_FTy>::CreateFrom(std::declval<_FTy>()))
{
return detail::continuable_factory_t<_FTy>::CreateFrom(std::forward<_FTy>(functional));
}
#endif // _CONTINUABLE_H_