Loki/include/loki/SmartPtr.h
rich_sposato d723342f30 Changed functions in all policies from public to protected.
git-svn-id: svn://svn.code.sf.net/p/loki-lib/code/trunk@1029 7ec92016-0320-0410-acc4-a06ded1c099a
2009-10-07 00:41:02 +00:00

1798 lines
52 KiB
C++

////////////////////////////////////////////////////////////////////////////////
// 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_
// $Id$
/// \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*
protected:
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)
{}
explicit 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);
// 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*
protected:
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)
{}
explicit 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);
// 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:
explicit 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*
protected:
LockedStorage() : pointee_( Default() ) {}
~LockedStorage( void ) {}
LockedStorage( const LockedStorage&) : pointee_( 0 ) {}
explicit LockedStorage( const StoredType & p ) : pointee_( p ) {}
PointerType operator->() const
{
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);
// 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*
protected:
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)
{}
explicit 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);
// 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
{
protected:
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 >
{
public:
typedef ThreadingModel< RefCountedMT<P>, MX > base_type;
typedef typename base_type::IntType CountType;
typedef volatile CountType *CountPtrType;
protected:
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
{
protected:
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
{
protected:
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
{
protected:
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
{
protected:
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
{
protected:
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
{
protected:
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
{
protected:
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
{
protected:
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
{
protected:
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
{
protected:
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
{
protected:
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
{
protected:
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 ( 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 ( 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 ( 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 ( lhs < GetImpl( rhs ) );
}
////////////////////////////////////////////////////////////////////////////////
// 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 < GetImpl( 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