ConnectionBody.hpp

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#ifndef DART_COMMON_DETAIL_CONNECTIONBODY_HPP_
#define DART_COMMON_DETAIL_CONNECTIONBODY_HPP_

#include <memory>

namespace dart {
namespace common {

namespace signal {
namespace detail {

class ConnectionBodyBase
{
public:
  ConnectionBodyBase() = default;

  virtual ~ConnectionBodyBase();

  virtual void disconnect() = 0;
};

template <typename SignalType>
class ConnectionBody final
  : public ConnectionBodyBase,
    public std::enable_shared_from_this<ConnectionBody<SignalType>>
{
public:
  using SlotType = typename SignalType::SlotType;

  ConnectionBody(SignalType& signal, const SlotType& _slot);

  ConnectionBody(SignalType& signal, SlotType&& _slot);

  virtual ~ConnectionBody();

  void disconnect() override;

  const SlotType& getSlot() const;

private:
  SignalType& mSignal;
  // Holding the reference of the Signal is safe because the lifetime of this
  // ConnectionBody is always shorter than the Signal since the Signal has the
  // ownership of this ConnectionBody.

  SlotType mSlot;
};

//==============================================================================
template <typename SignalType>
ConnectionBody<SignalType>::ConnectionBody(
    SignalType& signal, const SlotType& _slot)
  : ConnectionBodyBase(), mSignal(signal), mSlot(_slot)
{
  // Do nothing
}

//==============================================================================
template <typename SignalType>
ConnectionBody<SignalType>::ConnectionBody(SignalType& signal, SlotType&& _slot)
  : ConnectionBodyBase(), mSignal(signal), mSlot(std::forward<SlotType>(_slot))
{
  // Do nothing
}

//==============================================================================
template <typename SignalType>
ConnectionBody<SignalType>::~ConnectionBody()
{
  // Do nothing
}

//==============================================================================
template <typename SignalType>
void ConnectionBody<SignalType>::disconnect()
{
  mSignal.disconnect(this->shared_from_this());
}

//==============================================================================
template <typename SignalType>
const typename ConnectionBody<SignalType>::SlotType&
ConnectionBody<SignalType>::getSlot() const
{
  return mSlot;
}

template <typename T>
struct DefaultCombiner
{
  typedef T result_type;

  template <typename InputIterator>
  static T process(InputIterator first, InputIterator last)
  {
    // If there are no slots to call, just return the
    // default-constructed value
    if (first == last)
      return T();

    return *(--last);
  }
};

} // namespace detail
} // namespace signal

} // namespace common
} // namespace dart

#endif // DART_COMMON_DETAIL_CONNECTIONBODY_HPP_