/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef SELF_REF_H
#define SELF_REF_H

#include "mozilla/Attributes.h"

namespace mozilla {

template<class T>
class SelfReference {
public:
  SelfReference() : mHeld(false) {}
  ~SelfReference()
  {
    NS_ASSERTION(!mHeld, "Forgot to drop the self reference?");
  }

  void Take(T* t)
  {
    if (!mHeld) {
      mHeld = true;
      t->AddRef();
    }
  }
  void Drop(T* t)
  {
    if (mHeld) {
      mHeld = false;
      t->Release();
    }
  }

  MOZ_IMPLICIT operator bool() const { return mHeld; }

  SelfReference(const SelfReference& aOther) = delete;
  void operator=(const SelfReference& aOther) = delete;
private:
  bool mHeld;
};

} // namespace mozilla

#endif // SELF_REF_H
