vertex.h

#ifndef CYCLE_PTR_DETAIL_VERTEX_H
#define CYCLE_PTR_DETAIL_VERTEX_H

#include <cycle_ptr/detail/intrusive_ptr.h>
#include <cycle_ptr/detail/llist.h>
#include <cycle_ptr/detail/hazard.h>

namespace cycle_ptr::detail {


class base_control;
class generation;

class vertex
: public link<vertex>
{
  friend class generation;
  friend class base_control;

 protected:
  vertex();

  vertex([[maybe_unused]] const vertex& other)
  : vertex()
  {}

  explicit vertex(intrusive_ptr<base_control> bc) noexcept;
  ~vertex() noexcept;

  auto reset() -> void;

  auto reset(
      intrusive_ptr<base_control> new_dst,
      bool has_reference,
      bool no_red_promotion)
  -> void;

  auto owner_is_expired() const noexcept -> bool;

  auto throw_if_owner_expired() const
  -> void {
    if (owner_is_expired()) throw std::bad_weak_ptr();
  }

 public:
  auto get_control() const noexcept -> intrusive_ptr<base_control>;

 private:
  const intrusive_ptr<base_control> bc_; // Non-null.
  hazard_ptr<base_control> dst_;
};


} /* namespace cycle_ptr::detail */

#endif /* CYCLE_PTR_DETAIL_VERTEX_H */