ptr.h

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/*
 * Copyright (c) 2005,2006 INRIA
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
 */
 
#ifndef PTR_H
#define PTR_H
 
#include "assert.h"
 
#include <iostream>
#include <stdint.h>
 
namespace ns3
{
 
template <typename T>
class Ptr
{
  private:
    T* m_ptr;
 
    friend class Ptr<const T>;
 
    template <typename U>
    friend U* GetPointer(const Ptr<U>& p);
    template <typename U>
    friend U* PeekPointer(const Ptr<U>& p);
 
    inline void Acquire() const;
 
  public:
    Ptr();
    Ptr(T* ptr);
    Ptr(T* ptr, bool ref);
    Ptr(const Ptr& o);
    template <typename U>
    Ptr(const Ptr<U>& o);
    ~Ptr();
    Ptr<T>& operator=(const Ptr& o);
    T* operator->() const;
    T* operator->();
    T& operator*() const;
    T& operator*();
 
    explicit operator bool() const;
};
 
template <typename T, typename... Ts>
Ptr<T> Create(Ts&&... args);
 
template <typename T>
std::ostream& operator<<(std::ostream& os, const Ptr<T>& p);
 
template <typename T1, typename T2>
bool operator==(const Ptr<T1>& lhs, T2 const* rhs);
 
template <typename T1, typename T2>
bool operator==(T1 const* lhs, Ptr<T2>& rhs);
 
template <typename T1, typename T2>
bool operator==(const Ptr<T1>& lhs, const Ptr<T2>& rhs);
template <typename T1, typename T2>
std::enable_if_t<std::is_same_v<T2, std::nullptr_t>, bool> operator==(const Ptr<T1>& lhs, T2 rhs);
 
template <typename T1, typename T2>
bool operator!=(const Ptr<T1>& lhs, T2 const* rhs);
 
template <typename T1, typename T2>
bool operator!=(T1 const* lhs, Ptr<T2>& rhs);
 
template <typename T1, typename T2>
bool operator!=(const Ptr<T1>& lhs, const Ptr<T2>& rhs);
template <typename T1, typename T2>
std::enable_if_t<std::is_same_v<T2, std::nullptr_t>, bool> operator!=(const Ptr<T1>& lhs, T2 rhs);
 
template <typename T>
bool operator<(const Ptr<T>& lhs, const Ptr<T>& rhs);
template <typename T>
bool operator<(const Ptr<T>& lhs, const Ptr<const T>& rhs);
template <typename T>
bool operator<(const Ptr<const T>& lhs, const Ptr<T>& rhs);
template <typename T>
bool operator<=(const Ptr<T>& lhs, const Ptr<T>& rhs);
template <typename T>
bool operator>(const Ptr<T>& lhs, const Ptr<T>& rhs);
template <typename T>
bool operator>=(const Ptr<T>& lhs, const Ptr<T>& rhs);
template <typename T1, typename T2>
Ptr<T1> const_pointer_cast(const Ptr<T2>& p);
 
// Duplicate of struct CallbackTraits<T> as defined in callback.h
template <typename T>
struct CallbackTraits;
 
template <typename T>
struct CallbackTraits<Ptr<T>>
{
    static T& GetReference(const Ptr<T> p)
    {
        return *PeekPointer(p);
    }
};
 
// Duplicate of struct EventMemberImplObjTraits<T> as defined in make-event.h
// We repeat it here to declare a specialization on Ptr<T>
// without making this header dependent on make-event.h
template <typename T>
struct EventMemberImplObjTraits;
 
template <typename T>
struct EventMemberImplObjTraits<Ptr<T>>
{
    static T& GetReference(Ptr<T> p)
    {
        return *PeekPointer(p);
    }
};
 
} // namespace ns3
 
namespace ns3
{
 
/*************************************************
 *  friend non-member function implementations
 ************************************************/
 
template <typename T, typename... Ts>
Ptr<T>
Create(Ts&&... args)
{
    return Ptr<T>(new T(std::forward<Ts>(args)...), false);
}
 
template <typename U>
U*
PeekPointer(const Ptr<U>& p)
{
    return p.m_ptr;
}
 
template <typename U>
U*
GetPointer(const Ptr<U>& p)
{
    p.Acquire();
    return p.m_ptr;
}
 
template <typename T>
std::ostream&
operator<<(std::ostream& os, const Ptr<T>& p)
{
    os << PeekPointer(p);
    return os;
}
 
template <typename T1, typename T2>
bool
operator==(const Ptr<T1>& lhs, T2 const* rhs)
{
    return PeekPointer(lhs) == rhs;
}
 
template <typename T1, typename T2>
bool
operator==(T1 const* lhs, Ptr<T2>& rhs)
{
    return lhs == PeekPointer(rhs);
}
 
template <typename T1, typename T2>
bool
operator!=(const Ptr<T1>& lhs, T2 const* rhs)
{
    return PeekPointer(lhs) != rhs;
}
 
template <typename T1, typename T2>
bool
operator!=(T1 const* lhs, Ptr<T2>& rhs)
{
    return lhs != PeekPointer(rhs);
}
 
template <typename T1, typename T2>
bool
operator==(const Ptr<T1>& lhs, const Ptr<T2>& rhs)
{
    return PeekPointer(lhs) == PeekPointer(rhs);
}
 
template <typename T1, typename T2>
bool
operator!=(const Ptr<T1>& lhs, const Ptr<T2>& rhs)
{
    return PeekPointer(lhs) != PeekPointer(rhs);
}
 
template <typename T1, typename T2>
std::enable_if_t<std::is_same_v<T2, std::nullptr_t>, bool>
operator==(const Ptr<T1>& lhs, T2 rhs)
{
    return PeekPointer(lhs) == nullptr;
}
 
template <typename T1, typename T2>
std::enable_if_t<std::is_same_v<T2, std::nullptr_t>, bool>
operator!=(const Ptr<T1>& lhs, T2 rhs)
{
    return PeekPointer(lhs) != nullptr;
}
 
template <typename T>
bool
operator<(const Ptr<T>& lhs, const Ptr<T>& rhs)
{
    return PeekPointer<T>(lhs) < PeekPointer<T>(rhs);
}
 
template <typename T>
bool
operator<(const Ptr<T>& lhs, const Ptr<const T>& rhs)
{
    return PeekPointer<T>(lhs) < PeekPointer<const T>(rhs);
}
 
template <typename T>
bool
operator<(const Ptr<const T>& lhs, const Ptr<T>& rhs)
{
    return PeekPointer<const T>(lhs) < PeekPointer<T>(rhs);
}
 
template <typename T>
bool
operator<=(const Ptr<T>& lhs, const Ptr<T>& rhs)
{
    return PeekPointer<T>(lhs) <= PeekPointer<T>(rhs);
}
 
template <typename T>
bool
operator>(const Ptr<T>& lhs, const Ptr<T>& rhs)
{
    return PeekPointer<T>(lhs) > PeekPointer<T>(rhs);
}
 
template <typename T>
bool
operator>=(const Ptr<T>& lhs, const Ptr<T>& rhs)
{
    return PeekPointer<T>(lhs) >= PeekPointer<T>(rhs);
}
 
template <typename T1, typename T2>
Ptr<T1>
ConstCast(const Ptr<T2>& p)
{
    return Ptr<T1>(const_cast<T1*>(PeekPointer(p)));
}
 
template <typename T1, typename T2>
Ptr<T1>
DynamicCast(const Ptr<T2>& p)
{
    return Ptr<T1>(dynamic_cast<T1*>(PeekPointer(p)));
}
 
template <typename T1, typename T2>
Ptr<T1>
StaticCast(const Ptr<T2>& p)
{
    return Ptr<T1>(static_cast<T1*>(PeekPointer(p)));
}
 
template <typename T>
Ptr<T>
Copy(Ptr<T> object)
{
    Ptr<T> p = Ptr<T>(new T(*PeekPointer(object)), false);
    return p;
}
 
template <typename T>
Ptr<T>
Copy(Ptr<const T> object)
{
    Ptr<T> p = Ptr<T>(new T(*PeekPointer(object)), false);
    return p;
}
 
/****************************************************
 *      Member method implementations.
 ***************************************************/
 
template <typename T>
void
Ptr<T>::Acquire() const
{
    if (m_ptr != nullptr)
    {
        m_ptr->Ref();
    }
}
 
template <typename T>
Ptr<T>::Ptr()
    : m_ptr(nullptr)
{
}
 
template <typename T>
Ptr<T>::Ptr(T* ptr)
    : m_ptr(ptr)
{
    Acquire();
}
 
template <typename T>
Ptr<T>::Ptr(T* ptr, bool ref)
    : m_ptr(ptr)
{
    if (ref)
    {
        Acquire();
    }
}
 
template <typename T>
Ptr<T>::Ptr(const Ptr& o)
    : m_ptr(nullptr)
{
    T* ptr = PeekPointer(o);
    if (ptr != nullptr)
    {
        m_ptr = ptr;
        Acquire();
    }
}
 
template <typename T>
template <typename U>
Ptr<T>::Ptr(const Ptr<U>& o)
    : m_ptr(PeekPointer(o))
{
    Acquire();
}
 
template <typename T>
Ptr<T>::~Ptr()
{
    if (m_ptr != nullptr)
    {
        m_ptr->Unref();
    }
}
 
template <typename T>
Ptr<T>&
Ptr<T>::operator=(const Ptr& o)
{
    if (&o == this)
    {
        return *this;
    }
    if (m_ptr != nullptr)
    {
        m_ptr->Unref();
    }
    m_ptr = o.m_ptr;
    Acquire();
    return *this;
}
 
template <typename T>
T*
Ptr<T>::operator->()
{
    NS_ASSERT_MSG(m_ptr, "Attempted to dereference zero pointer");
    return m_ptr;
}
 
template <typename T>
T*
Ptr<T>::operator->() const
{
    NS_ASSERT_MSG(m_ptr, "Attempted to dereference zero pointer");
    return m_ptr;
}
 
template <typename T>
T&
Ptr<T>::operator*() const
{
    NS_ASSERT_MSG(m_ptr, "Attempted to dereference zero pointer");
    return *m_ptr;
}
 
template <typename T>
T&
Ptr<T>::operator*()
{
    NS_ASSERT_MSG(m_ptr, "Attempted to dereference zero pointer");
    return *m_ptr;
}
 
template <typename T>
Ptr<T>::operator bool() const
{
    return m_ptr != nullptr;
}
 
} // namespace ns3
 
/****************************************************
 *      Global Functions (outside namespace ns3)
 ***************************************************/
 
template <class T>
struct std::hash<ns3::Ptr<T>>
{
    std::size_t operator()(ns3::Ptr<T> p) const
    {
        return std::hash<const T*>()(ns3::PeekPointer(p));
    }
};
 
#endif /* PTR_H */