OpenDX/src/util/rc/util_rc_ptr.h

#pragma once

#include <functional>
#include <ostream>

namespace dxvk {
  
  /**
   * \brief Pointer for reference-counted objects
   * 
   * This only requires the given type to implement \c incRef
   * and \c decRef methods that adjust the reference count.
   * \tparam T Object type
   */
  template<typename T>
  class Rc {
    template<typename Tx>
    friend class Rc;
  public:
    
    Rc() { }
    Rc(std::nullptr_t) { }
    
    Rc(T* object)
    : m_object(object) {
      this->incRef();
    }
    
    Rc(const Rc& other)
    : m_object(other.m_object) {
      this->incRef();
    }
    
    template<typename Tx>
    Rc(const Rc<Tx>& other)
    : m_object(other.m_object) {
      this->incRef();
    }
    
    Rc(Rc&& other)
    : m_object(other.m_object) {
      other.m_object = nullptr;
    }
    
    template<typename Tx>
    Rc(Rc<Tx>&& other)
    : m_object(other.m_object) {
      other.m_object = nullptr;
    }
    
    Rc& operator = (std::nullptr_t) {
      this->decRef();
      m_object = nullptr;
      return *this;
    }
    
    Rc& operator = (const Rc& other) {
      other.incRef();
      this->decRef();
      m_object = other.m_object;
      return *this;
    }
    
    template<typename Tx>
    Rc& operator = (const Rc<Tx>& other) {
      other.incRef();
      this->decRef();
      m_object = other.m_object;
      return *this;
    }
    
    Rc& operator = (Rc&& other) {
      this->decRef();
      this->m_object = other.m_object;
      other.m_object = nullptr;
      return *this;
    }
    
    template<typename Tx>
    Rc& operator = (Rc<Tx>&& other) {
      this->decRef();
      this->m_object = other.m_object;
      other.m_object = nullptr;
      return *this;
    }
    
    ~Rc() {
      this->decRef();
    }
    
    T& operator *  () const { return *m_object; }
    T* operator -> () const { return  m_object; }
    T* ptr() const { return m_object; }
    
    bool operator == (const Rc& other) const { return m_object == other.m_object; }
    bool operator != (const Rc& other) const { return m_object != other.m_object; }
    
    bool operator == (std::nullptr_t) const { return m_object == nullptr; }
    bool operator != (std::nullptr_t) const { return m_object != nullptr; }
    
  private:
    
    T* m_object = nullptr;
    
    void incRef() const {
      if (m_object != nullptr)
        m_object->incRef();
    }
    
    void decRef() const {
      if (m_object != nullptr) {
        if (m_object->decRef() == 0)
          delete m_object;
      }
    }
    
  };
  
}

template<typename T>
std::ostream& operator << (std::ostream& os, const dxvk::Rc<T>& rc) {
  return os << rc.ptr();
}