/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* 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