AutoRef.h

// -*- tab-width: 2; indent-tabs-mode: nil; coding: utf-8-with-signature -*-
//-----------------------------------------------------------------------------
// Copyright 2000-2024 CEA (www.cea.fr) IFPEN (www.ifpenergiesnouvelles.com)
// See the top-level COPYRIGHT file for details.
// SPDX-License-Identifier: Apache-2.0
//-----------------------------------------------------------------------------
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/* AutoRef.h                                                   (C) 2000-2024 */
/*                                                                           */
/* Encapsulation d'un pointeur avec compteur de référence.                   */
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#ifndef ARCANE_UTILS_AUTOREF_H
#define ARCANE_UTILS_AUTOREF_H
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#include "arcane/utils/Ptr.h"
 
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namespace Arcane
{
 
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template <class T>
class AutoRefT
: public PtrT<T>
{
 public:
 
  using BaseClass = PtrT<T>;
 
  using BaseClass::m_value;
 
 public:
 
  AutoRefT() = default;
  explicit AutoRefT(T* t)
  : BaseClass()
  {
    _changeValue(t);
  }
  AutoRefT(const AutoRefT<T>& from)
  : BaseClass()
  {
    _changeValue(from.m_value);
  }
 
  AutoRefT<T>& operator=(const AutoRefT<T>& from)
  {
    _changeValue(from.m_value);
    return (*this);
  }
 
  AutoRefT<T>& operator=(T* new_value)
  {
    _changeValue(new_value);
    return (*this);
  }
 
  ~AutoRefT() { _removeRef(); }
 
 private:
 
  void _addRef()
  {
    if (m_value)
      m_value->addRef();
  }
  void _removeRef()
  {
    if (m_value)
      m_value->removeRef();
  }
  void _changeValue(T* new_value)
  {
    if (m_value == new_value)
      return;
    _removeRef();
    m_value = new_value;
    _addRef();
  }
};
 
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template <class T>
class AutoRef2
{
 public:
 
  using ThatClass = AutoRef2<T>;
 
 public:
 
  AutoRef2() = default;
  explicit AutoRef2(T* t)
  {
    _changeValue(t);
  }
  AutoRef2(const ThatClass& from)
  {
    _changeValue(from.m_value);
  }
  AutoRef2(ThatClass&& from) noexcept
  : m_value(from.m_value)
  {
    from.m_value = nullptr;
  }
 
  ThatClass& operator=(const ThatClass& from)
  {
    _changeValue(from.m_value);
    return (*this);
  }
  ThatClass& operator=(ThatClass&& from) noexcept
  {
    _removeRef();
    m_value = from.m_value;
    from.m_value = nullptr;
    return (*this);
  }
 
  ThatClass& operator=(T* new_value)
  {
    _changeValue(new_value);
    return (*this);
  }
 
  ~AutoRef2() { _removeRef(); }
 
  T* operator->() const
  {
    ARCANE_CHECK_PTR(m_value);
    return m_value;
  }
 
  inline T& operator*() const
  {
    ARCANE_CHECK_PTR(m_value);
    return *m_value;
  }
 
  T* get() const { return m_value; }
 
  bool isNull() const { return !m_value; }
  operator bool() const { return m_value; }
 
  friend bool operator==(const ThatClass& a, const ThatClass& b)
  {
    return a.get() == b.get();
  }
  friend bool operator!=(const ThatClass& a, const ThatClass& b)
  {
    return a.get() != b.get();
  }
 
 private:
 
  void _addRef()
  {
    if (m_value)
      m_value->addRef();
  }
  void _removeRef()
  {
    if (m_value)
      m_value->removeRef();
  }
  void _changeValue(T* new_value)
  {
    if (m_value == new_value)
      return;
    _removeRef();
    m_value = new_value;
    _addRef();
  }
 
 private:
 
  T* m_value = nullptr; 
};
 
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} // namespace Arcane
 
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#endif