CheckedPointer.h

// -*- tab-width: 2; indent-tabs-mode: nil; coding: utf-8-with-signature -*-
//-----------------------------------------------------------------------------
// Copyright 2000-2026 CEA (www.cea.fr) IFPEN (www.ifpenergiesnouvelles.com)
// See the top-level COPYRIGHT file for details.
// SPDX-License-Identifier: Apache-2.0
//-----------------------------------------------------------------------------
/*---------------------------------------------------------------------------*/
/* CheckedPointer.h                                            (C) 2000-2025 */
/*                                                                           */
/* Classes encapsulating a pointer allowing usage checking.                  */
/*---------------------------------------------------------------------------*/
#ifndef ARCCORE_BASE_CHECKEDPOINTER_H
#define ARCCORE_BASE_CHECKEDPOINTER_H
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
#include "arccore/base/ArccoreGlobal.h"
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
namespace Arcane
{
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/

template <class T>
class CheckedPointer
{
 protected:

  const CheckedPointer<T>& operator=(const CheckedPointer<T>& from)
  {
    m_value = from.m_value;
    return (*this);
  }
 
  template <typename T2>
  const CheckedPointer<T>& operator=(const CheckedPointer<T2>& from)
  {
    m_value = from.get();
    return (*this);
  }

  const CheckedPointer<T>& operator=(T* new_value)
  {
    m_value = new_value;
    return (*this);
  }

  CheckedPointer(const CheckedPointer<T>& from)
  : m_value(from.m_value)
  {}

  template <typename T2>
  CheckedPointer(const CheckedPointer<T2>& from)
  : m_value(from.m_value)
  {}
 
 public:

  CheckedPointer()
  : m_value(nullptr)
  {}

  explicit CheckedPointer(T* t)
  : m_value(t)
  {}
 
 public:
 
  explicit operator bool() const { return get() != nullptr; }
 
 public:

  inline T* operator->() const
  {
#ifdef ARCCORE_CHECK
    if (!m_value)
      arccoreNullPointerError();
#endif
    return m_value;
  }

  inline T& operator*() const
  {
#ifdef ARCCORE_CHECK
    if (!m_value)
      arccoreNullPointerError();
#endif
    return *m_value;
  }

  inline T* get() const
  {
    return m_value;
  }
 
  inline bool isNull() const
  {
    return (!m_value);
  }

  template <typename T2> friend bool
  operator==(const CheckedPointer<T>& v1, const CheckedPointer<T2>& v2)
  {
    return v1.get() == v2.get();
  }

  template <typename T2> friend bool
  operator!=(const CheckedPointer<T>& v1, const CheckedPointer<T2>& v2)
  {
    return v1.get() != v2.get();
  }
 
 protected:
 
  T* m_value; 
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
} // namespace Arcane
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
#endif