////////////////////////////////////////////////////////////////////////////////
// The Loki Library
// Copyright (c) 2001 by Andrei Alexandrescu
// This code accompanies the book:
// Alexandrescu, Andrei. "Modern C++ Design: Generic Programming and Design
//     Patterns Applied". Copyright (c) 2001. Addison-Wesley.
// Permission to use, copy, modify, distribute and sell this software for any
//     purpose is hereby granted without fee, provided that the above copyright
//     notice appear in all copies and that both that copyright notice and this
//     permission notice appear in supporting documentation.
// The author or Addison-Wesley Longman make no representations about the
//     suitability of this software for any purpose. It is provided "as is"
//     without express or implied warranty.
////////////////////////////////////////////////////////////////////////////////
#ifndef LOKI_SMARTPTR_INC_
#define LOKI_SMARTPTR_INC_

// $Id: SmartPtr.h 903 2008-11-10 05:55:12Z rich_sposato $


///  \defgroup  SmartPointerGroup Smart pointers
///  Policy based implementation of a smart pointer
///  \defgroup  SmartPointerOwnershipGroup Ownership policies
///  \ingroup   SmartPointerGroup
///  \defgroup  SmartPointerStorageGroup Storage policies
///  \ingroup   SmartPointerGroup
///  \defgroup  SmartPointerConversionGroup Conversion policies
///  \ingroup   SmartPointerGroup
///  \defgroup  SmartPointerCheckingGroup Checking policies
///  \ingroup   SmartPointerGroup

#include "LokiExport.h"
#include "SmallObj.h"
#include "TypeManip.h"
#include "static_check.h"
#include "RefToValue.h"
#include "ConstPolicy.h"

#include <functional>
#include <stdexcept>
#include <cassert>
#include <string>

#if !defined(_MSC_VER)
#  if defined(__sparc__)
#    include <inttypes.h>
#  else
#    include <stdint.h>
#  endif
#endif

#if defined(_MSC_VER) || defined(__GNUC__)
// GCC>=4.1 must use -ffriend-injection due to a bug in GCC
#define LOKI_ENABLE_FRIEND_TEMPLATE_TEMPLATE_PARAMETER_WORKAROUND
#endif


namespace Loki
{

////////////////////////////////////////////////////////////////////////////////
///  \class HeapStorage
///
///  \ingroup  SmartPointerStorageGroup
///  Implementation of the StoragePolicy used by SmartPtr.  Uses explicit call
///   to T's destructor followed by call to free.
////////////////////////////////////////////////////////////////////////////////


template <class T>
class HeapStorage
{
public:
    typedef T* StoredType;      /// the type of the pointee_ object
    typedef T* InitPointerType; /// type used to declare OwnershipPolicy type.
    typedef T* PointerType;     /// type returned by operator->
    typedef T& ReferenceType;   /// type returned by operator*

    HeapStorage() : pointee_(Default())
    {}

    // The storage policy doesn't initialize the stored pointer
    //     which will be initialized by the OwnershipPolicy's Clone fn
    HeapStorage(const HeapStorage&) : pointee_(0)
    {}

    template <class U>
    HeapStorage(const HeapStorage<U>&) : pointee_(0)
    {}

    HeapStorage(const StoredType& p) : pointee_(p) {}

    PointerType operator->() const { return pointee_; }

    ReferenceType operator*() const { return *pointee_; }

    void Swap(HeapStorage& rhs)
    { std::swap(pointee_, rhs.pointee_); }

    // Accessors
    template <class F>
    friend typename HeapStorage<F>::PointerType GetImpl(const HeapStorage<F>& sp);

    template <class F>
    friend const typename HeapStorage<F>::StoredType& GetImplRef(const HeapStorage<F>& sp);

    template <class F>
    friend typename HeapStorage<F>::StoredType& GetImplRef(HeapStorage<F>& sp);

protected:
    // Destroys the data stored
    // (Destruction might be taken over by the OwnershipPolicy)
    void Destroy()
    {
        if ( 0 != pointee_ )
        {
            pointee_->~T();
            ::free( pointee_ );
        }
    }

    // Default value to initialize the pointer
    static StoredType Default()
    { return 0; }

private:
    // Data
    StoredType pointee_;
};

template <class T>
inline typename HeapStorage<T>::PointerType GetImpl(const HeapStorage<T>& sp)
{ return sp.pointee_; }

template <class T>
inline const typename HeapStorage<T>::StoredType& GetImplRef(const HeapStorage<T>& sp)
{ return sp.pointee_; }

template <class T>
inline typename HeapStorage<T>::StoredType& GetImplRef(HeapStorage<T>& sp)
{ return sp.pointee_; }


////////////////////////////////////////////////////////////////////////////////
///  \class DefaultSPStorage
///
///  \ingroup  SmartPointerStorageGroup
///  Implementation of the StoragePolicy used by SmartPtr
////////////////////////////////////////////////////////////////////////////////


template <class T>
class DefaultSPStorage
{
public:
    typedef T* StoredType;    // the type of the pointee_ object
    typedef T* InitPointerType; /// type used to declare OwnershipPolicy type.
    typedef T* PointerType;   // type returned by operator->
    typedef T& ReferenceType; // type returned by operator*

    DefaultSPStorage() : pointee_(Default())
    {}

    // The storage policy doesn't initialize the stored pointer
    //     which will be initialized by the OwnershipPolicy's Clone fn
    DefaultSPStorage(const DefaultSPStorage&) : pointee_(0)
    {}

    template <class U>
    DefaultSPStorage(const DefaultSPStorage<U>&) : pointee_(0)
    {}

    DefaultSPStorage(const StoredType& p) : pointee_(p) {}

    PointerType operator->() const { return pointee_; }

    ReferenceType operator*() const { return *pointee_; }

    void Swap(DefaultSPStorage& rhs)
    { std::swap(pointee_, rhs.pointee_); }

    // Accessors
    template <class F>
    friend typename DefaultSPStorage<F>::PointerType GetImpl(const DefaultSPStorage<F>& sp);

    template <class F>
    friend const typename DefaultSPStorage<F>::StoredType& GetImplRef(const DefaultSPStorage<F>& sp);

    template <class F>
    friend typename DefaultSPStorage<F>::StoredType& GetImplRef(DefaultSPStorage<F>& sp);

protected:
    // Destroys the data stored
    // (Destruction might be taken over by the OwnershipPolicy)
    //
    // If your compiler gives you a warning in this area while
    // compiling the tests, it is on purpose, please ignore it.
    void Destroy()
    {
        delete pointee_;
    }

    // Default value to initialize the pointer
    static StoredType Default()
    { return 0; }

private:
    // Data
    StoredType pointee_;
};

template <class T>
inline typename DefaultSPStorage<T>::PointerType GetImpl(const DefaultSPStorage<T>& sp)
{ return sp.pointee_; }

template <class T>
inline const typename DefaultSPStorage<T>::StoredType& GetImplRef(const DefaultSPStorage<T>& sp)
{ return sp.pointee_; }

template <class T>
inline typename DefaultSPStorage<T>::StoredType& GetImplRef(DefaultSPStorage<T>& sp)
{ return sp.pointee_; }


////////////////////////////////////////////////////////////////////////////////
///  \class LockedStorage
///
///  \ingroup  SmartPointerStorageGroup
///  Implementation of the StoragePolicy used by SmartPtr.
///
///  Each call to operator-> locks the object for the duration of a call to a
///  member function of T.
///
///  \par How It Works
///  LockedStorage has a helper class called Locker, which acts as a smart
///  pointer with limited abilities.  LockedStorage::operator-> returns an
///  unnamed temporary of type Locker<T> that exists for the duration of the
///  call to a member function of T.  The unnamed temporary locks the object
///  when it is constructed by operator-> and unlocks the object when it is
///  destructed.
///
///  \note This storage policy requires class T to have member functions Lock
///  and Unlock.  If your class does not have Lock or Unlock functions, you may
///  either make a child class which does, or make a policy class similar to
///  LockedStorage which calls other functions to lock the object.
////////////////////////////////////////////////////////////////////////////////

template <class T>
class Locker
{
public:
    Locker( const T* p ) : pointee_( const_cast< T* >( p ) )
    {
        if ( pointee_ != 0 )
            pointee_->Lock();
    }

    ~Locker( void )
    {
        if ( pointee_ != 0 )
            pointee_->Unlock();
    }

    operator T* ()
    {
        return pointee_;
    }

    T* operator->()
    {
        return pointee_;
    }

private:
    Locker( void );
    Locker& operator = ( const Locker& );
    T* pointee_;
};

template <class T>
class LockedStorage
{
public:

    typedef T* StoredType;           /// the type of the pointee_ object
    typedef T* InitPointerType;      /// type used to declare OwnershipPolicy type.
    typedef Locker< T > PointerType; /// type returned by operator->
    typedef T& ReferenceType;        /// type returned by operator*

    LockedStorage() : pointee_( Default() ) {}

    ~LockedStorage( void ) {}

    LockedStorage( const LockedStorage&) : pointee_( 0 ) {}

    LockedStorage( const StoredType& p ) : pointee_( p ) {}

    PointerType operator->()
    {
        return Locker< T >( pointee_ );
    }

    void Swap(LockedStorage& rhs)
    {
        std::swap( pointee_, rhs.pointee_ );
    }

    // Accessors
    template <class F>
    friend typename LockedStorage<F>::InitPointerType GetImpl(const LockedStorage<F>& sp);

    template <class F>
    friend const typename LockedStorage<F>::StoredType& GetImplRef(const LockedStorage<F>& sp);

    template <class F>
    friend typename LockedStorage<F>::StoredType& GetImplRef(LockedStorage<F>& sp);

protected:
    // Destroys the data stored
    // (Destruction might be taken over by the OwnershipPolicy)
    void Destroy()
    {
        delete pointee_;
    }

    // Default value to initialize the pointer
    static StoredType Default()
    { return 0; }

private:
    /// Dereference operator is not implemented.
    ReferenceType operator*();

    // Data
    StoredType pointee_;
};

template <class T>
inline typename LockedStorage<T>::InitPointerType GetImpl(const LockedStorage<T>& sp)
{ return sp.pointee_; }

template <class T>
inline const typename LockedStorage<T>::StoredType& GetImplRef(const LockedStorage<T>& sp)
{ return sp.pointee_; }

template <class T>
inline typename LockedStorage<T>::StoredType& GetImplRef(LockedStorage<T>& sp)
{ return sp.pointee_; }


////////////////////////////////////////////////////////////////////////////////
///  \class ArrayStorage
///
///  \ingroup  SmartPointerStorageGroup
///  Implementation of the ArrayStorage used by SmartPtr
////////////////////////////////////////////////////////////////////////////////


template <class T>
class ArrayStorage
{
public:
    typedef T* StoredType;    // the type of the pointee_ object
    typedef T* InitPointerType; /// type used to declare OwnershipPolicy type.
    typedef T* PointerType;   // type returned by operator->
    typedef T& ReferenceType; // type returned by operator*

    ArrayStorage() : pointee_(Default())
    {}

    // The storage policy doesn't initialize the stored pointer
    //     which will be initialized by the OwnershipPolicy's Clone fn
    ArrayStorage(const ArrayStorage&) : pointee_(0)
    {}

    template <class U>
    ArrayStorage(const ArrayStorage<U>&) : pointee_(0)
    {}

    ArrayStorage(const StoredType& p) : pointee_(p) {}

    PointerType operator->() const { return pointee_; }

    ReferenceType operator*() const { return *pointee_; }

    void Swap(ArrayStorage& rhs)
    { std::swap(pointee_, rhs.pointee_); }

    // Accessors
    template <class F>
    friend typename ArrayStorage<F>::PointerType GetImpl(const ArrayStorage<F>& sp);

    template <class F>
    friend const typename ArrayStorage<F>::StoredType& GetImplRef(const ArrayStorage<F>& sp);

    template <class F>
    friend typename ArrayStorage<F>::StoredType& GetImplRef(ArrayStorage<F>& sp);

protected:
    // Destroys the data stored
    // (Destruction might be taken over by the OwnershipPolicy)
    void Destroy()
    { delete [] pointee_; }

    // Default value to initialize the pointer
    static StoredType Default()
    { return 0; }

private:
    // Data
    StoredType pointee_;
};

template <class T>
inline typename ArrayStorage<T>::PointerType GetImpl(const ArrayStorage<T>& sp)
{ return sp.pointee_; }

template <class T>
inline const typename ArrayStorage<T>::StoredType& GetImplRef(const ArrayStorage<T>& sp)
{ return sp.pointee_; }

template <class T>
inline typename ArrayStorage<T>::StoredType& GetImplRef(ArrayStorage<T>& sp)
{ return sp.pointee_; }


////////////////////////////////////////////////////////////////////////////////
///  \class RefCounted
///
///  \ingroup  SmartPointerOwnershipGroup
///  Implementation of the OwnershipPolicy used by SmartPtr
///  Provides a classic external reference counting implementation
////////////////////////////////////////////////////////////////////////////////

template <class P>
class RefCounted
{
public:
    RefCounted()
        : pCount_(static_cast<uintptr_t*>(
                      SmallObject<>::operator new(sizeof(uintptr_t))))
    {
        assert(pCount_!=0);
        *pCount_ = 1;
    }

    RefCounted(const RefCounted& rhs)
        : pCount_(rhs.pCount_)
    {}

    // MWCW lacks template friends, hence the following kludge
    template <typename P1>
    RefCounted(const RefCounted<P1>& rhs)
        : pCount_(reinterpret_cast<const RefCounted&>(rhs).pCount_)
    {}

    P Clone(const P& val)
    {
        ++*pCount_;
        return val;
    }

    bool Release(const P&)
    {
        if (!--*pCount_)
        {
            SmallObject<>::operator delete(pCount_, sizeof(uintptr_t));
            pCount_ = NULL;
            return true;
        }
        return false;
    }

    void Swap(RefCounted& rhs)
    { std::swap(pCount_, rhs.pCount_); }

    enum { destructiveCopy = false };

private:
    // Data
    uintptr_t* pCount_;
};

////////////////////////////////////////////////////////////////////////////////
///  \struct RefCountedMT
///
///  \ingroup  SmartPointerOwnershipGroup
///  Implementation of the OwnershipPolicy used by SmartPtr
///  Implements external reference counting for multithreaded programs
///  Policy Usage: RefCountedMTAdj<ThreadingModel>::RefCountedMT
///
///  \par Warning
///  There could be a race condition, see bug "Race condition in RefCountedMTAdj::Release"
///  http://sourceforge.net/tracker/index.php?func=detail&aid=1408845&group_id=29557&atid=396644
///  As stated in bug 1408845, the Release function is not thread safe if a
///  SmartPtr copy-constructor tries to copy the last pointer to an object in
///  one thread, while the destructor is acting on the last pointer in another
///  thread.  The existence of a race between a copy-constructor and destructor
///  implies a design flaw at a higher level.  That race condition must be
///  fixed at a higher design level, and no change to this class could fix it.
////////////////////////////////////////////////////////////////////////////////

template <template <class, class> class ThreadingModel,
         class MX = LOKI_DEFAULT_MUTEX >
struct RefCountedMTAdj
{
    template <class P>
    class RefCountedMT : public ThreadingModel< RefCountedMT<P>, MX >
    {
        typedef ThreadingModel< RefCountedMT<P>, MX > base_type;
        typedef typename base_type::IntType       CountType;
        typedef volatile CountType*               CountPtrType;

    public:
        RefCountedMT()
        {
            pCount_ = static_cast<CountPtrType>(
                          SmallObject<LOKI_DEFAULT_THREADING_NO_OBJ_LEVEL>::operator new(
                              sizeof(*pCount_)));
            assert(pCount_);
            //*pCount_ = 1;
            ThreadingModel<RefCountedMT, MX>::AtomicAssign(*pCount_, 1);
        }

        RefCountedMT(const RefCountedMT& rhs)
            : pCount_(rhs.pCount_)
        {}

        //MWCW lacks template friends, hence the following kludge
        template <typename P1>
        RefCountedMT(const RefCountedMT<P1>& rhs)
            : pCount_(reinterpret_cast<const RefCountedMT<P>&>(rhs).pCount_)
        {}

        P Clone(const P& val)
        {
            ThreadingModel<RefCountedMT, MX>::AtomicIncrement(*pCount_);
            return val;
        }

        bool Release(const P&)
        {
            bool isZero = false;
            ThreadingModel< RefCountedMT, MX >::AtomicDecrement( *pCount_, 0, isZero );
            if ( isZero )
            {
                SmallObject<LOKI_DEFAULT_THREADING_NO_OBJ_LEVEL>::operator delete(
                    const_cast<CountType*>(pCount_),
                    sizeof(*pCount_));
                return true;
            }
            return false;
        }

        void Swap(RefCountedMT& rhs)
        { std::swap(pCount_, rhs.pCount_); }

        enum { destructiveCopy = false };

    private:
        // Data
        CountPtrType pCount_;
    };
};

////////////////////////////////////////////////////////////////////////////////
///  \class COMRefCounted
///
///  \ingroup  SmartPointerOwnershipGroup
///  Implementation of the OwnershipPolicy used by SmartPtr
///  Adapts COM intrusive reference counting to OwnershipPolicy-specific syntax
////////////////////////////////////////////////////////////////////////////////

template <class P>
class COMRefCounted
{
public:
    COMRefCounted()
    {}

    template <class U>
    COMRefCounted(const COMRefCounted<U>&)
    {}

    static P Clone(const P& val)
    {
        if(val!=0)
            val->AddRef();
        return val;
    }

    static bool Release(const P& val)
    {
        if(val!=0)
            val->Release();
        return false;
    }

    enum { destructiveCopy = false };

    static void Swap(COMRefCounted&)
    {}
};

////////////////////////////////////////////////////////////////////////////////
///  \struct DeepCopy
///
///  \ingroup  SmartPointerOwnershipGroup
///  Implementation of the OwnershipPolicy used by SmartPtr
///  Implements deep copy semantics, assumes existence of a Clone() member
///  function of the pointee type
////////////////////////////////////////////////////////////////////////////////

template <class P>
struct DeepCopy
{
    DeepCopy()
    {}

    template <class P1>
    DeepCopy(const DeepCopy<P1>&)
    {}

    static P Clone(const P& val)
    { return val->Clone(); }

    static bool Release(const P&)
    { return true; }

    static void Swap(DeepCopy&)
    {}

    enum { destructiveCopy = false };
};

////////////////////////////////////////////////////////////////////////////////
///  \class RefLinked
///
///  \ingroup  SmartPointerOwnershipGroup
///  Implementation of the OwnershipPolicy used by SmartPtr
///  Implements reference linking
////////////////////////////////////////////////////////////////////////////////

namespace Private
{
class LOKI_EXPORT RefLinkedBase
{
public:
    RefLinkedBase()
    { prev_ = next_ = this; }

    RefLinkedBase(const RefLinkedBase& rhs);

    bool Release();

    void Swap(RefLinkedBase& rhs);

    bool Merge( RefLinkedBase& rhs );

    enum { destructiveCopy = false };

private:
    static unsigned int CountPrevCycle( const RefLinkedBase* pThis );
    static unsigned int CountNextCycle( const RefLinkedBase* pThis );
    bool HasPrevNode( const RefLinkedBase* p ) const;
    bool HasNextNode( const RefLinkedBase* p ) const;

    mutable const RefLinkedBase* prev_;
    mutable const RefLinkedBase* next_;
};
}

template <class P>
class RefLinked : public Private::RefLinkedBase
{
public:
    RefLinked()
    {}

    template <class P1>
    RefLinked(const RefLinked<P1>& rhs)
        : Private::RefLinkedBase(rhs)
    {}

    static P Clone(const P& val)
    { return val; }

    bool Release(const P&)
    { return Private::RefLinkedBase::Release(); }

    template < class P1 >
    bool Merge( RefLinked< P1 > & rhs )
    {
        return Private::RefLinkedBase::Merge( rhs );
    }
};

////////////////////////////////////////////////////////////////////////////////
///  \class DestructiveCopy
///
///  \ingroup  SmartPointerOwnershipGroup
///  Implementation of the OwnershipPolicy used by SmartPtr
///  Implements destructive copy semantics (a la std::auto_ptr)
////////////////////////////////////////////////////////////////////////////////

template <class P>
class DestructiveCopy
{
public:
    DestructiveCopy()
    {}

    template <class P1>
    DestructiveCopy(const DestructiveCopy<P1>&)
    {}

    template <class P1>
    static P Clone(P1& val)
    {
        P result(val);
        val = P1();
        return result;
    }

    static bool Release(const P&)
    { return true; }

    static void Swap(DestructiveCopy&)
    {}

    enum { destructiveCopy = true };
};

////////////////////////////////////////////////////////////////////////////////
///  \class NoCopy
///
///  \ingroup  SmartPointerOwnershipGroup
///  Implementation of the OwnershipPolicy used by SmartPtr
///  Implements a policy that doesn't allow copying objects
////////////////////////////////////////////////////////////////////////////////

template <class P>
class NoCopy
{
public:
    NoCopy()
    {}

    template <class P1>
    NoCopy(const NoCopy<P1>&)
    {}

    static P Clone(const P&)
    {
        // Make it depended on template parameter
        static const bool DependedFalse = sizeof(P*) == 0;

        LOKI_STATIC_CHECK(DependedFalse, This_Policy_Disallows_Value_Copying);
    }

    static bool Release(const P&)
    { return true; }

    static void Swap(NoCopy&)
    {}

    enum { destructiveCopy = false };
};

////////////////////////////////////////////////////////////////////////////////
///  \struct AllowConversion
///
///  \ingroup  SmartPointerConversionGroup
///  Implementation of the ConversionPolicy used by SmartPtr
///  Allows implicit conversion from SmartPtr to the pointee type
////////////////////////////////////////////////////////////////////////////////

struct AllowConversion
{
    enum { allow = true };

    void Swap(AllowConversion&)
    {}
};

////////////////////////////////////////////////////////////////////////////////
///  \struct DisallowConversion
///
///  \ingroup  SmartPointerConversionGroup
///  Implementation of the ConversionPolicy used by SmartPtr
///  Does not allow implicit conversion from SmartPtr to the pointee type
///  You can initialize a DisallowConversion with an AllowConversion
////////////////////////////////////////////////////////////////////////////////

struct DisallowConversion
{
    DisallowConversion()
    {}

    DisallowConversion(const AllowConversion&)
    {}

    enum { allow = false };

    void Swap(DisallowConversion&)
    {}
};

////////////////////////////////////////////////////////////////////////////////
///  \struct NoCheck
///
///  \ingroup  SmartPointerCheckingGroup
///  Implementation of the CheckingPolicy used by SmartPtr
///  Well, it's clear what it does :o)
////////////////////////////////////////////////////////////////////////////////

template <class P>
struct NoCheck
{
    NoCheck()
    {}

    template <class P1>
    NoCheck(const NoCheck<P1>&)
    {}

    static void OnDefault(const P&)
    {}

    static void OnInit(const P&)
    {}

    static void OnDereference(const P&)
    {}

    static void Swap(NoCheck&)
    {}
};


////////////////////////////////////////////////////////////////////////////////
///  \struct AssertCheck
///
///  \ingroup  SmartPointerCheckingGroup
///  Implementation of the CheckingPolicy used by SmartPtr
///  Checks the pointer before dereference
////////////////////////////////////////////////////////////////////////////////

template <class P>
struct AssertCheck
{
    AssertCheck()
    {}

    template <class P1>
    AssertCheck(const AssertCheck<P1>&)
    {}

    template <class P1>
    AssertCheck(const NoCheck<P1>&)
    {}

    static void OnDefault(const P&)
    {}

    static void OnInit(const P&)
    {}

    static void OnDereference(P val)
    { assert(val); (void)val; }

    static void Swap(AssertCheck&)
    {}
};

////////////////////////////////////////////////////////////////////////////////
///  \struct AssertCheckStrict
///
///  \ingroup  SmartPointerCheckingGroup
///  Implementation of the CheckingPolicy used by SmartPtr
///  Checks the pointer against zero upon initialization and before dereference
///  You can initialize an AssertCheckStrict with an AssertCheck
////////////////////////////////////////////////////////////////////////////////

template <class P>
struct AssertCheckStrict
{
    AssertCheckStrict()
    {}

    template <class U>
    AssertCheckStrict(const AssertCheckStrict<U>&)
    {}

    template <class U>
    AssertCheckStrict(const AssertCheck<U>&)
    {}

    template <class P1>
    AssertCheckStrict(const NoCheck<P1>&)
    {}

    static void OnDefault(P val)
    { assert(val); }

    static void OnInit(P val)
    { assert(val); }

    static void OnDereference(P val)
    { assert(val); }

    static void Swap(AssertCheckStrict&)
    {}
};

////////////////////////////////////////////////////////////////////////////////
///  \struct NullPointerException
///
///  \ingroup SmartPointerGroup
///  Used by some implementations of the CheckingPolicy used by SmartPtr
////////////////////////////////////////////////////////////////////////////////

struct NullPointerException : public std::runtime_error
{
    NullPointerException() : std::runtime_error(std::string(""))
    { }
    const char* what() const throw()
    { return "Null Pointer Exception"; }
};

////////////////////////////////////////////////////////////////////////////////
///  \struct RejectNullStatic
///
///  \ingroup  SmartPointerCheckingGroup
///  Implementation of the CheckingPolicy used by SmartPtr
///  Checks the pointer upon initialization and before dereference
////////////////////////////////////////////////////////////////////////////////

template <class P>
struct RejectNullStatic
{
    RejectNullStatic()
    {}

    template <class P1>
    RejectNullStatic(const RejectNullStatic<P1>&)
    {}

    template <class P1>
    RejectNullStatic(const NoCheck<P1>&)
    {}

    template <class P1>
    RejectNullStatic(const AssertCheck<P1>&)
    {}

    template <class P1>
    RejectNullStatic(const AssertCheckStrict<P1>&)
    {}

    static void OnDefault(const P&)
    {
        // Make it depended on template parameter
        static const bool DependedFalse = sizeof(P*) == 0;

        LOKI_STATIC_CHECK(DependedFalse, ERROR_This_Policy_Does_Not_Allow_Default_Initialization);
    }

    static void OnInit(const P& val)
    { if (!val) throw NullPointerException(); }

    static void OnDereference(const P& val)
    { if (!val) throw NullPointerException(); }

    static void Swap(RejectNullStatic&)
    {}
};

////////////////////////////////////////////////////////////////////////////////
///  \struct RejectNull
///
///  \ingroup  SmartPointerCheckingGroup
///  Implementation of the CheckingPolicy used by SmartPtr
///  Checks the pointer before dereference
////////////////////////////////////////////////////////////////////////////////

template <class P>
struct RejectNull
{
    RejectNull()
    {}

    template <class P1>
    RejectNull(const RejectNull<P1>&)
    {}

    static void OnInit(P)
    {}

    static void OnDefault(P)
    {}

    void OnDereference(P val)
    { if (!val) throw NullPointerException(); }

    void OnDereference(P val) const
    { if (!val) throw NullPointerException(); }

    void Swap(RejectNull&)
    {}
};

////////////////////////////////////////////////////////////////////////////////
///  \struct RejectNullStrict
///
///  \ingroup  SmartPointerCheckingGroup
///  Implementation of the CheckingPolicy used by SmartPtr
///  Checks the pointer upon initialization and before dereference
////////////////////////////////////////////////////////////////////////////////

template <class P>
struct RejectNullStrict
{
    RejectNullStrict()
    {}

    template <class P1>
    RejectNullStrict(const RejectNullStrict<P1>&)
    {}

    template <class P1>
    RejectNullStrict(const RejectNull<P1>&)
    {}

    static void OnInit(P val)
    { if (!val) throw NullPointerException(); }

    void OnDereference(P val)
    { OnInit(val); }

    void OnDereference(P val) const
    { OnInit(val); }

    void Swap(RejectNullStrict&)
    {}
};


////////////////////////////////////////////////////////////////////////////////
// class template SmartPtr (declaration)
// The reason for all the fuss above
////////////////////////////////////////////////////////////////////////////////

template
<
typename T,
         template <class> class OwnershipPolicy = RefCounted,
         class ConversionPolicy = DisallowConversion,
         template <class> class CheckingPolicy = AssertCheck,
         template <class> class StoragePolicy = DefaultSPStorage,
         template<class> class ConstnessPolicy = LOKI_DEFAULT_CONSTNESS
         >
class SmartPtr;

////////////////////////////////////////////////////////////////////////////////
// class template SmartPtrDef (definition)
// this class added to unify the usage of SmartPtr
// instead of writing SmartPtr<T,OP,CP,KP,SP> write SmartPtrDef<T,OP,CP,KP,SP>::type
////////////////////////////////////////////////////////////////////////////////

template
<
typename T,
         template <class> class OwnershipPolicy = RefCounted,
         class ConversionPolicy = DisallowConversion,
         template <class> class CheckingPolicy = AssertCheck,
         template <class> class StoragePolicy = DefaultSPStorage,
         template<class> class ConstnessPolicy = LOKI_DEFAULT_CONSTNESS
         >
struct SmartPtrDef
{
    typedef SmartPtr
    <
    T,
    OwnershipPolicy,
    ConversionPolicy,
    CheckingPolicy,
    StoragePolicy,
    ConstnessPolicy
    >
    type;
};

////////////////////////////////////////////////////////////////////////////////
///  \class SmartPtr
///
///  \ingroup SmartPointerGroup
///
///  \param OwnershipPolicy  default =  RefCounted,
///  \param ConversionPolicy default = DisallowConversion,
///  \param CheckingPolicy default = AssertCheck,
///  \param StoragePolicy default = DefaultSPStorage
///  \param ConstnessPolicy default = LOKI_DEFAULT_CONSTNESS
///
///  \par IMPORTANT NOTE
///  Due to threading issues, the OwnershipPolicy has been changed as follows:
///
///     - Release() returns a boolean saying if that was the last release
///        so the pointer can be deleted by the StoragePolicy
///     - IsUnique() was removed
////////////////////////////////////////////////////////////////////////////////

template
<
typename T,
         template <class> class OwnershipPolicy,
         class ConversionPolicy,
         template <class> class CheckingPolicy,
         template <class> class StoragePolicy,
         template <class> class ConstnessPolicy
         >
class SmartPtr
    : public StoragePolicy<T>
    , public OwnershipPolicy<typename StoragePolicy<T>::InitPointerType>
    , public CheckingPolicy<typename StoragePolicy<T>::StoredType>
    , public ConversionPolicy
{
    typedef StoragePolicy<T> SP;
    typedef OwnershipPolicy<typename StoragePolicy<T>::InitPointerType> OP;
    typedef CheckingPolicy<typename StoragePolicy<T>::StoredType> KP;
    typedef ConversionPolicy CP;

public:
    typedef typename ConstnessPolicy<T>::Type* ConstPointerType;
    typedef typename ConstnessPolicy<T>::Type& ConstReferenceType;

    typedef typename SP::PointerType PointerType;
    typedef typename SP::StoredType StoredType;
    typedef typename SP::ReferenceType ReferenceType;

    typedef typename Select<OP::destructiveCopy,SmartPtr, const SmartPtr>::Result
    CopyArg;

private:
    struct NeverMatched {};

#ifdef LOKI_SMARTPTR_CONVERSION_CONSTRUCTOR_POLICY
    typedef typename Select< CP::allow, const StoredType&, NeverMatched>::Result ImplicitArg;
    typedef typename Select<!CP::allow, const StoredType&, NeverMatched>::Result ExplicitArg;
#else
    typedef const StoredType& ImplicitArg;
    typedef typename Select<false, const StoredType&, NeverMatched>::Result ExplicitArg;
#endif

public:

    SmartPtr()
    {
        KP::OnDefault(GetImpl(*this));
    }

    explicit
    SmartPtr(ExplicitArg p) : SP(p)
    {
        KP::OnInit(GetImpl(*this));
    }

    SmartPtr(ImplicitArg p) : SP(p)
    {
        KP::OnInit(GetImpl(*this));
    }

    SmartPtr(CopyArg& rhs) : SP(rhs), OP(rhs), KP(rhs), CP(rhs)
    {
        GetImplRef(*this) = OP::Clone(GetImplRef(rhs));
    }

    template
    <
    typename T1,
             template <class> class OP1,
             class CP1,
             template <class> class KP1,
             template <class> class SP1,
             template <class> class CNP1
             >
    SmartPtr(const SmartPtr<T1, OP1, CP1, KP1, SP1, CNP1 >& rhs)
        : SP(rhs), OP(rhs), KP(rhs), CP(rhs)
    { GetImplRef(*this) = OP::Clone(GetImplRef(rhs)); }

    template
    <
    typename T1,
             template <class> class OP1,
             class CP1,
             template <class> class KP1,
             template <class> class SP1,
             template <class> class CNP1
             >
    SmartPtr(SmartPtr<T1, OP1, CP1, KP1, SP1, CNP1 >& rhs)
        : SP(rhs), OP(rhs), KP(rhs), CP(rhs)
    {
        GetImplRef(*this) = OP::Clone(GetImplRef(rhs));
    }

    SmartPtr(RefToValue<SmartPtr> rhs)
        : SP(rhs), OP(rhs), KP(rhs), CP(rhs)
    {}

    operator RefToValue<SmartPtr>()
    { return RefToValue<SmartPtr>(*this); }

    SmartPtr& operator=(CopyArg& rhs)
    {
        SmartPtr temp(rhs);
        temp.Swap(*this);
        return *this;
    }

    template
    <
    typename T1,
             template <class> class OP1,
             class CP1,
             template <class> class KP1,
             template <class> class SP1,
             template <class> class CNP1
             >
    SmartPtr& operator=(const SmartPtr<T1, OP1, CP1, KP1, SP1, CNP1 >& rhs)
    {
        SmartPtr temp(rhs);
        temp.Swap(*this);
        return *this;
    }

    template
    <
    typename T1,
             template <class> class OP1,
             class CP1,
             template <class> class KP1,
             template <class> class SP1,
             template <class> class CNP1
             >
    SmartPtr& operator=(SmartPtr<T1, OP1, CP1, KP1, SP1, CNP1 >& rhs)
    {
        SmartPtr temp(rhs);
        temp.Swap(*this);
        return *this;
    }

    void Swap(SmartPtr& rhs)
    {
        OP::Swap(rhs);
        CP::Swap(rhs);
        KP::Swap(rhs);
        SP::Swap(rhs);
    }

    ~SmartPtr()
    {
        if (OP::Release(GetImpl(*static_cast<SP*>(this))))
        {
            SP::Destroy();
        }
    }

#ifdef LOKI_ENABLE_FRIEND_TEMPLATE_TEMPLATE_PARAMETER_WORKAROUND

    // old non standard in class definition of friends
    friend inline void Release(SmartPtr& sp, typename SP::StoredType& p)
    {
        p = GetImplRef(sp);
        GetImplRef(sp) = SP::Default();
    }

    friend inline void Reset(SmartPtr& sp, typename SP::StoredType p)
    { SmartPtr(p).Swap(sp); }

#else

    template
    <
    typename T1,
             template <class> class OP1,
             class CP1,
             template <class> class KP1,
             template <class> class SP1,
             template <class> class CNP1
             >
    friend void Release(SmartPtr<T1, OP1, CP1, KP1, SP1, CNP1>& sp,
                        typename SP1<T1>::StoredType& p);

    template
    <
    typename T1,
             template <class> class OP1,
             class CP1,
             template <class> class KP1,
             template <class> class SP1,
             template <class> class CNP1
             >
    friend void Reset(SmartPtr<T1, OP1, CP1, KP1, SP1, CNP1>& sp,
                      typename SP1<T1>::StoredType p);
#endif


    template
    <
    typename T1,
             template <class> class OP1,
             class CP1,
             template <class> class KP1,
             template <class> class SP1,
             template <class> class CNP1
             >
    bool Merge( SmartPtr< T1, OP1, CP1, KP1, SP1, CNP1 > & rhs )
    {
        if ( GetImpl( *this ) != GetImpl( rhs ) )
        {
            return false;
        }
        return OP::template Merge( rhs );
    }

    PointerType operator->()
    {
        KP::OnDereference(GetImplRef(*this));
        return SP::operator->();
    }

    ConstPointerType operator->() const
    {
        KP::OnDereference(GetImplRef(*this));
        return SP::operator->();
    }

    ReferenceType operator*()
    {
        KP::OnDereference(GetImplRef(*this));
        return SP::operator*();
    }

    ConstReferenceType operator*() const
    {
        KP::OnDereference(GetImplRef(*this));
        return SP::operator*();
    }

    bool operator!() const // Enables "if (!sp) ..."
    { return GetImpl(*this) == 0; }

    static inline T* GetPointer( const SmartPtr& sp )
    { return GetImpl( sp ); }

    // Ambiguity buster
    template
    <
    typename T1,
             template <class> class OP1,
             class CP1,
             template <class> class KP1,
             template <class> class SP1,
             template <class> class CNP1
             >
    bool operator==(const SmartPtr<T1, OP1, CP1, KP1, SP1, CNP1 >& rhs) const
    { return GetImpl(*this) == GetImpl(rhs); }

    // Ambiguity buster
    template
    <
    typename T1,
             template <class> class OP1,
             class CP1,
             template <class> class KP1,
             template <class> class SP1,
             template <class> class CNP1
             >
    bool operator!=(const SmartPtr<T1, OP1, CP1, KP1, SP1, CNP1 >& rhs) const
    { return !(*this == rhs); }

    // Ambiguity buster
    template
    <
    typename T1,
             template <class> class OP1,
             class CP1,
             template <class> class KP1,
             template <class> class SP1,
             template <class> class CNP1
             >
    bool operator<(const SmartPtr<T1, OP1, CP1, KP1, SP1, CNP1 >& rhs) const
    { return GetImpl(*this) < GetImpl(rhs); }

    // Ambiguity buster
    template
    <
    typename T1,
             template <class> class OP1,
             class CP1,
             template <class> class KP1,
             template <class> class SP1,
             template <class> class CNP1
             >
    inline bool operator > ( const SmartPtr< T1, OP1, CP1, KP1, SP1, CNP1 > & rhs )
    {
        return ( GetImpl( rhs ) < GetImpl( *this ) );
    }

    // Ambiguity buster
    template
    <
    typename T1,
             template <class> class OP1,
             class CP1,
             template <class> class KP1,
             template <class> class SP1,
             template <class> class CNP1
             >
    inline bool operator <= ( const SmartPtr< T1, OP1, CP1, KP1, SP1, CNP1 > & rhs )
    {
        return !( GetImpl( rhs ) < GetImpl( *this ) );
    }

    // Ambiguity buster
    template
    <
    typename T1,
             template <class> class OP1,
             class CP1,
             template <class> class KP1,
             template <class> class SP1,
             template <class> class CNP1
             >
    inline bool operator >= ( const SmartPtr< T1, OP1, CP1, KP1, SP1, CNP1 > & rhs )
    {
        return !( GetImpl( *this ) < GetImpl( rhs ) );
    }

private:
    // Helper for enabling 'if (sp)'
    struct Tester
    {
        Tester(int) {}
        void dummy() {}
    };

    typedef void (Tester::*unspecified_boolean_type_)();

    typedef typename Select<CP::allow, Tester, unspecified_boolean_type_>::Result
    unspecified_boolean_type;

public:
    // enable 'if (sp)'
    operator unspecified_boolean_type() const
    {
        return !*this ? 0 : &Tester::dummy;
    }

private:
    // Helper for disallowing automatic conversion
    struct Insipid
    {
        Insipid(PointerType) {}
    };

    typedef typename Select<CP::allow, PointerType, Insipid>::Result
    AutomaticConversionResult;

public:
    operator AutomaticConversionResult() const
    { return GetImpl(*this); }
};


////////////////////////////////////////////////////////////////////////////////
// friends
////////////////////////////////////////////////////////////////////////////////

#ifndef LOKI_ENABLE_FRIEND_TEMPLATE_TEMPLATE_PARAMETER_WORKAROUND

template
<
typename T,
         template <class> class OP,
         class CP,
         template <class> class KP,
         template <class> class SP,
         template <class> class CNP
         >
inline void Release(SmartPtr<T, OP, CP, KP, SP, CNP>& sp,
                    typename SP<T>::StoredType& p)
{
    p = GetImplRef(sp);
    GetImplRef(sp) = SP<T>::Default();
}

template
<
typename T,
         template <class> class OP,
         class CP,
         template <class> class KP,
         template <class> class SP,
         template <class> class CNP
         >
inline void Reset(SmartPtr<T, OP, CP, KP, SP, CNP>& sp,
                  typename SP<T>::StoredType p)
{ SmartPtr<T, OP, CP, KP, SP, CNP>(p).Swap(sp); }

#endif

////////////////////////////////////////////////////////////////////////////////
// free comparison operators for class template SmartPtr
////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////
///  operator== for lhs = SmartPtr, rhs = raw pointer
///  \ingroup SmartPointerGroup
////////////////////////////////////////////////////////////////////////////////

template
<
typename T,
         template <class> class OP,
         class CP,
         template <class> class KP,
         template <class> class SP,
         template <class> class CNP1,
         typename U
         >
inline bool operator==(const SmartPtr<T, OP, CP, KP, SP, CNP1 >& lhs,
                       U* rhs)
{ return GetImpl(lhs) == rhs; }

////////////////////////////////////////////////////////////////////////////////
///  operator== for lhs = raw pointer, rhs = SmartPtr
///  \ingroup SmartPointerGroup
////////////////////////////////////////////////////////////////////////////////

template
<
typename T,
         template <class> class OP,
         class CP,
         template <class> class KP,
         template <class> class SP,
         template <class> class CNP1,
         typename U
         >
inline bool operator==(U* lhs,
                       const SmartPtr<T, OP, CP, KP, SP, CNP1 >& rhs)
{ return rhs == lhs; }

////////////////////////////////////////////////////////////////////////////////
///  operator!= for lhs = SmartPtr, rhs = raw pointer
///  \ingroup SmartPointerGroup
////////////////////////////////////////////////////////////////////////////////

template
<
typename T,
         template <class> class OP,
         class CP,
         template <class> class KP,
         template <class> class SP,
         template <class> class CNP,
         typename U
         >
inline bool operator!=(const SmartPtr<T, OP, CP, KP, SP, CNP >& lhs,
                       U* rhs)
{ return !(lhs == rhs); }

////////////////////////////////////////////////////////////////////////////////
///  operator!= for lhs = raw pointer, rhs = SmartPtr
///  \ingroup SmartPointerGroup
////////////////////////////////////////////////////////////////////////////////

template
<
typename T,
         template <class> class OP,
         class CP,
         template <class> class KP,
         template <class> class SP,
         template <class> class CNP,
         typename U
         >
inline bool operator!=(U* lhs,
                       const SmartPtr<T, OP, CP, KP, SP, CNP >& rhs)
{ return rhs != lhs; }

////////////////////////////////////////////////////////////////////////////////
///  operator< for lhs = SmartPtr, rhs = raw pointer
///  \ingroup SmartPointerGroup
////////////////////////////////////////////////////////////////////////////////

template
<
typename T,
         template <class> class OP,
         class CP,
         template <class> class KP,
         template <class> class SP,
         template <class> class CNP,
         typename U
         >
inline bool operator<(const SmartPtr<T, OP, CP, KP, SP, CNP >& lhs,
                      U* rhs)
{
    return ( GetImpl( lhs ) < rhs );
}

////////////////////////////////////////////////////////////////////////////////
///  operator< for lhs = raw pointer, rhs = SmartPtr
///  \ingroup SmartPointerGroup
////////////////////////////////////////////////////////////////////////////////

template
<
typename T,
         template <class> class OP,
         class CP,
         template <class> class KP,
         template <class> class SP,
         template <class> class CNP,
         typename U
         >
inline bool operator<(U* lhs,
                      const SmartPtr<T, OP, CP, KP, SP, CNP >& rhs)
{
    return ( GetImpl( rhs ) < lhs );
}

////////////////////////////////////////////////////////////////////////////////
//  operator> for lhs = SmartPtr, rhs = raw pointer
///  \ingroup SmartPointerGroup
////////////////////////////////////////////////////////////////////////////////

template
<
typename T,
         template <class> class OP,
         class CP,
         template <class> class KP,
         template <class> class SP,
         template <class> class CNP,
         typename U
         >
inline bool operator>(const SmartPtr<T, OP, CP, KP, SP, CNP >& lhs,
                      U* rhs)
{ return rhs < lhs; }

////////////////////////////////////////////////////////////////////////////////
///  operator> for lhs = raw pointer, rhs = SmartPtr
///  \ingroup SmartPointerGroup
////////////////////////////////////////////////////////////////////////////////

template
<
typename T,
         template <class> class OP,
         class CP,
         template <class> class KP,
         template <class> class SP,
         template <class> class CNP,
         typename U
         >
inline bool operator>(U* lhs,
                      const SmartPtr<T, OP, CP, KP, SP, CNP >& rhs)
{ return rhs < lhs; }

////////////////////////////////////////////////////////////////////////////////
///  operator<= for lhs = SmartPtr, rhs = raw pointer
///  \ingroup SmartPointerGroup
////////////////////////////////////////////////////////////////////////////////

template
<
typename T,
         template <class> class OP,
         class CP,
         template <class> class KP,
         template <class> class SP,
         template <class> class CNP,
         typename U
         >
inline bool operator<=(const SmartPtr<T, OP, CP, KP, SP, CNP >& lhs,
                       U* rhs)
{ return !(rhs < lhs); }

////////////////////////////////////////////////////////////////////////////////
///  operator<= for lhs = raw pointer, rhs = SmartPtr
///  \ingroup SmartPointerGroup
////////////////////////////////////////////////////////////////////////////////

template
<
typename T,
         template <class> class OP,
         class CP,
         template <class> class KP,
         template <class> class SP,
         template <class> class CNP,
         typename U
         >
inline bool operator<=(U* lhs,
                       const SmartPtr<T, OP, CP, KP, SP, CNP >& rhs)
{ return !(rhs < lhs); }

////////////////////////////////////////////////////////////////////////////////
///  operator>= for lhs = SmartPtr, rhs = raw pointer
///  \ingroup SmartPointerGroup
////////////////////////////////////////////////////////////////////////////////

template
<
typename T,
         template <class> class OP,
         class CP,
         template <class> class KP,
         template <class> class SP,
         template <class> class CNP,
         typename U
         >
inline bool operator>=(const SmartPtr<T, OP, CP, KP, SP, CNP >& lhs,
                       U* rhs)
{ return !(lhs < rhs); }

////////////////////////////////////////////////////////////////////////////////
///  operator>= for lhs = raw pointer, rhs = SmartPtr
///  \ingroup SmartPointerGroup
////////////////////////////////////////////////////////////////////////////////

template
<
typename T,
         template <class> class OP,
         class CP,
         template <class> class KP,
         template <class> class SP,
         template <class> class CNP,
         typename U
         >
inline bool operator>=(U* lhs,
                       const SmartPtr<T, OP, CP, KP, SP, CNP >& rhs)
{ return !(lhs < rhs); }

} // namespace Loki

////////////////////////////////////////////////////////////////////////////////
///  specialization of std::less for SmartPtr
///  \ingroup SmartPointerGroup
////////////////////////////////////////////////////////////////////////////////

namespace std
{
template
<
typename T,
         template <class> class OP,
         class CP,
         template <class> class KP,
         template <class> class SP,
         template <class> class CNP
         >
struct less< Loki::SmartPtr<T, OP, CP, KP, SP, CNP > >
        : public binary_function<Loki::SmartPtr<T, OP, CP, KP, SP, CNP >,
          Loki::SmartPtr<T, OP, CP, KP, SP, CNP >, bool>
{
    bool operator()(const Loki::SmartPtr<T, OP, CP, KP, SP, CNP >& lhs,
                    const Loki::SmartPtr<T, OP, CP, KP, SP, CNP >& rhs) const
    { return less<T*>()(GetImpl(lhs), GetImpl(rhs)); }
};
}

#endif // end file guardian