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gecko-dev/xpcom/base/nsAutoPtr.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Scott Collins <scc@mozilla.org> (original author of nsCOMPtr)
* L. David Baron <dbaron@dbaron.org>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef nsAutoPtr_h___
#define nsAutoPtr_h___
// Wrapping includes can speed up compiles (see "Large Scale C++ Software Design")
#ifndef nsCOMPtr_h___
// For |already_AddRefed|, |NSCAP_Zero|,
// |NSCAP_DONT_PROVIDE_NONCONST_OPEQ|,
// |NSCAP_FEATURE_INLINE_STARTASSIGNMENT|
#include "nsCOMPtr.h"
#endif
/*****************************************************************************/
// template <class T> class nsAutoPtrGetterTransfers;
template <class T>
class nsAutoPtr
{
private:
void**
begin_assignment()
{
assign(0);
return reinterpret_cast<void**>(&mRawPtr);
}
void
assign( T* newPtr )
{
T* oldPtr = mRawPtr;
mRawPtr = newPtr;
delete oldPtr;
}
// |class Ptr| helps us prevent implicit "copy construction"
// through |operator T*() const| from a |const nsAutoPtr<T>|
// because two implicit conversions in a row aren't allowed.
// It still allows assignment from T* through implicit conversion
// from |T*| to |nsAutoPtr<T>::Ptr|
class Ptr
{
public:
Ptr( T* aPtr )
: mPtr(aPtr)
{
}
operator T*() const
{
return mPtr;
}
private:
T* mPtr;
};
private:
T* mRawPtr;
public:
typedef T element_type;
~nsAutoPtr()
{
delete mRawPtr;
}
// Constructors
nsAutoPtr()
: mRawPtr(0)
// default constructor
{
}
nsAutoPtr( Ptr aRawPtr )
: mRawPtr(aRawPtr)
// construct from a raw pointer (of the right type)
{
}
nsAutoPtr( nsAutoPtr<T>& aSmartPtr )
: mRawPtr( aSmartPtr.forget() )
// Construct by transferring ownership from another smart pointer.
{
}
// Assignment operators
nsAutoPtr<T>&
operator=( T* rhs )
// assign from a raw pointer (of the right type)
{
assign(rhs);
return *this;
}
nsAutoPtr<T>& operator=( nsAutoPtr<T>& rhs )
// assign by transferring ownership from another smart pointer.
{
assign(rhs.forget());
return *this;
}
// Other pointer operators
T*
get() const
/*
Prefer the implicit conversion provided automatically by
|operator T*() const|. Use |get()| _only_ to resolve
ambiguity.
*/
{
return mRawPtr;
}
operator T*() const
/*
...makes an |nsAutoPtr| act like its underlying raw pointer
type whenever it is used in a context where a raw pointer
is expected. It is this operator that makes an |nsAutoPtr|
substitutable for a raw pointer.
Prefer the implicit use of this operator to calling |get()|,
except where necessary to resolve ambiguity.
*/
{
return get();
}
T*
forget()
{
T* temp = mRawPtr;
mRawPtr = 0;
return temp;
}
T*
operator->() const
{
NS_PRECONDITION(mRawPtr != 0, "You can't dereference a NULL nsAutoPtr with operator->().");
return get();
}
// This operator is needed for gcc <= 4.0.* and for Sun Studio; it
// causes internal compiler errors for some MSVC versions. (It's not
// clear to me whether it should be needed.)
#ifndef _MSC_VER
template <class U, class V>
U&
operator->*(U V::* aMember)
{
NS_PRECONDITION(mRawPtr != 0, "You can't dereference a NULL nsAutoPtr with operator->*().");
return get()->*aMember;
}
#endif
#ifdef CANT_RESOLVE_CPP_CONST_AMBIGUITY
// broken version for IRIX
nsAutoPtr<T>*
get_address() const
// This is not intended to be used by clients. See |address_of|
// below.
{
return const_cast<nsAutoPtr<T>*>(this);
}
#else // CANT_RESOLVE_CPP_CONST_AMBIGUITY
nsAutoPtr<T>*
get_address()
// This is not intended to be used by clients. See |address_of|
// below.
{
return this;
}
const nsAutoPtr<T>*
get_address() const
// This is not intended to be used by clients. See |address_of|
// below.
{
return this;
}
#endif // CANT_RESOLVE_CPP_CONST_AMBIGUITY
public:
T&
operator*() const
{
NS_PRECONDITION(mRawPtr != 0, "You can't dereference a NULL nsAutoPtr with operator*().");
return *get();
}
T**
StartAssignment()
{
#ifndef NSCAP_FEATURE_INLINE_STARTASSIGNMENT
return reinterpret_cast<T**>(begin_assignment());
#else
assign(0);
return reinterpret_cast<T**>(&mRawPtr);
#endif
}
};
#ifdef CANT_RESOLVE_CPP_CONST_AMBIGUITY
// This is the broken version for IRIX, which can't handle the version below.
template <class T>
inline
nsAutoPtr<T>*
address_of( const nsAutoPtr<T>& aPtr )
{
return aPtr.get_address();
}
#else // CANT_RESOLVE_CPP_CONST_AMBIGUITY
template <class T>
inline
nsAutoPtr<T>*
address_of( nsAutoPtr<T>& aPtr )
{
return aPtr.get_address();
}
template <class T>
inline
const nsAutoPtr<T>*
address_of( const nsAutoPtr<T>& aPtr )
{
return aPtr.get_address();
}
#endif // CANT_RESOLVE_CPP_CONST_AMBIGUITY
template <class T>
class nsAutoPtrGetterTransfers
/*
...
This class is designed to be used for anonymous temporary objects in the
argument list of calls that return COM interface pointers, e.g.,
nsAutoPtr<IFoo> fooP;
...->GetTransferedPointer(getter_Transfers(fooP))
DO NOT USE THIS TYPE DIRECTLY IN YOUR CODE. Use |getter_Transfers()| instead.
When initialized with a |nsAutoPtr|, as in the example above, it returns
a |void**|, a |T**|, or an |nsISupports**| as needed, that the
outer call (|GetTransferedPointer| in this case) can fill in.
This type should be a nested class inside |nsAutoPtr<T>|.
*/
{
public:
explicit
nsAutoPtrGetterTransfers( nsAutoPtr<T>& aSmartPtr )
: mTargetSmartPtr(aSmartPtr)
{
// nothing else to do
}
operator void**()
{
return reinterpret_cast<void**>(mTargetSmartPtr.StartAssignment());
}
operator T**()
{
return mTargetSmartPtr.StartAssignment();
}
T*&
operator*()
{
return *(mTargetSmartPtr.StartAssignment());
}
private:
nsAutoPtr<T>& mTargetSmartPtr;
};
template <class T>
inline
nsAutoPtrGetterTransfers<T>
getter_Transfers( nsAutoPtr<T>& aSmartPtr )
/*
Used around a |nsAutoPtr| when
...makes the class |nsAutoPtrGetterTransfers<T>| invisible.
*/
{
return nsAutoPtrGetterTransfers<T>(aSmartPtr);
}
// Comparing two |nsAutoPtr|s
template <class T, class U>
inline
NSCAP_BOOL
operator==( const nsAutoPtr<T>& lhs, const nsAutoPtr<U>& rhs )
{
return static_cast<const T*>(lhs.get()) == static_cast<const U*>(rhs.get());
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( const nsAutoPtr<T>& lhs, const nsAutoPtr<U>& rhs )
{
return static_cast<const T*>(lhs.get()) != static_cast<const U*>(rhs.get());
}
// Comparing an |nsAutoPtr| to a raw pointer
template <class T, class U>
inline
NSCAP_BOOL
operator==( const nsAutoPtr<T>& lhs, const U* rhs )
{
return static_cast<const T*>(lhs.get()) == static_cast<const U*>(rhs);
}
template <class T, class U>
inline
NSCAP_BOOL
operator==( const U* lhs, const nsAutoPtr<T>& rhs )
{
return static_cast<const U*>(lhs) == static_cast<const T*>(rhs.get());
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( const nsAutoPtr<T>& lhs, const U* rhs )
{
return static_cast<const T*>(lhs.get()) != static_cast<const U*>(rhs);
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( const U* lhs, const nsAutoPtr<T>& rhs )
{
return static_cast<const U*>(lhs) != static_cast<const T*>(rhs.get());
}
// To avoid ambiguities caused by the presence of builtin |operator==|s
// creating a situation where one of the |operator==| defined above
// has a better conversion for one argument and the builtin has a
// better conversion for the other argument, define additional
// |operator==| without the |const| on the raw pointer.
// See bug 65664 for details.
#ifndef NSCAP_DONT_PROVIDE_NONCONST_OPEQ
template <class T, class U>
inline
NSCAP_BOOL
operator==( const nsAutoPtr<T>& lhs, U* rhs )
{
return static_cast<const T*>(lhs.get()) == const_cast<const U*>(rhs);
}
template <class T, class U>
inline
NSCAP_BOOL
operator==( U* lhs, const nsAutoPtr<T>& rhs )
{
return const_cast<const U*>(lhs) == static_cast<const T*>(rhs.get());
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( const nsAutoPtr<T>& lhs, U* rhs )
{
return static_cast<const T*>(lhs.get()) != const_cast<const U*>(rhs);
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( U* lhs, const nsAutoPtr<T>& rhs )
{
return const_cast<const U*>(lhs) != static_cast<const T*>(rhs.get());
}
#endif
// Comparing an |nsAutoPtr| to |0|
template <class T>
inline
NSCAP_BOOL
operator==( const nsAutoPtr<T>& lhs, NSCAP_Zero* rhs )
// specifically to allow |smartPtr == 0|
{
return static_cast<const void*>(lhs.get()) == reinterpret_cast<const void*>(rhs);
}
template <class T>
inline
NSCAP_BOOL
operator==( NSCAP_Zero* lhs, const nsAutoPtr<T>& rhs )
// specifically to allow |0 == smartPtr|
{
return reinterpret_cast<const void*>(lhs) == static_cast<const void*>(rhs.get());
}
template <class T>
inline
NSCAP_BOOL
operator!=( const nsAutoPtr<T>& lhs, NSCAP_Zero* rhs )
// specifically to allow |smartPtr != 0|
{
return static_cast<const void*>(lhs.get()) != reinterpret_cast<const void*>(rhs);
}
template <class T>
inline
NSCAP_BOOL
operator!=( NSCAP_Zero* lhs, const nsAutoPtr<T>& rhs )
// specifically to allow |0 != smartPtr|
{
return reinterpret_cast<const void*>(lhs) != static_cast<const void*>(rhs.get());
}
#ifdef HAVE_CPP_TROUBLE_COMPARING_TO_ZERO
// We need to explicitly define comparison operators for `int'
// because the compiler is lame.
template <class T>
inline
NSCAP_BOOL
operator==( const nsAutoPtr<T>& lhs, int rhs )
// specifically to allow |smartPtr == 0|
{
return static_cast<const void*>(lhs.get()) == reinterpret_cast<const void*>(rhs);
}
template <class T>
inline
NSCAP_BOOL
operator==( int lhs, const nsAutoPtr<T>& rhs )
// specifically to allow |0 == smartPtr|
{
return reinterpret_cast<const void*>(lhs) == static_cast<const void*>(rhs.get());
}
#endif // !defined(HAVE_CPP_TROUBLE_COMPARING_TO_ZERO)
/*****************************************************************************/
// template <class T> class nsAutoArrayPtrGetterTransfers;
template <class T>
class nsAutoArrayPtr
{
private:
void**
begin_assignment()
{
assign(0);
return reinterpret_cast<void**>(&mRawPtr);
}
void
assign( T* newPtr )
{
T* oldPtr = mRawPtr;
mRawPtr = newPtr;
delete [] oldPtr;
}
private:
T* mRawPtr;
public:
typedef T element_type;
~nsAutoArrayPtr()
{
delete [] mRawPtr;
}
// Constructors
nsAutoArrayPtr()
: mRawPtr(0)
// default constructor
{
}
nsAutoArrayPtr( T* aRawPtr )
: mRawPtr(aRawPtr)
// construct from a raw pointer (of the right type)
{
}
nsAutoArrayPtr( nsAutoArrayPtr<T>& aSmartPtr )
: mRawPtr( aSmartPtr.forget() )
// Construct by transferring ownership from another smart pointer.
{
}
// Assignment operators
nsAutoArrayPtr<T>&
operator=( T* rhs )
// assign from a raw pointer (of the right type)
{
assign(rhs);
return *this;
}
nsAutoArrayPtr<T>& operator=( nsAutoArrayPtr<T>& rhs )
// assign by transferring ownership from another smart pointer.
{
assign(rhs.forget());
return *this;
}
// Other pointer operators
T*
get() const
/*
Prefer the implicit conversion provided automatically by
|operator T*() const|. Use |get()| _only_ to resolve
ambiguity.
*/
{
return mRawPtr;
}
operator T*() const
/*
...makes an |nsAutoArrayPtr| act like its underlying raw pointer
type whenever it is used in a context where a raw pointer
is expected. It is this operator that makes an |nsAutoArrayPtr|
substitutable for a raw pointer.
Prefer the implicit use of this operator to calling |get()|,
except where necessary to resolve ambiguity.
*/
{
return get();
}
T*
forget()
{
T* temp = mRawPtr;
mRawPtr = 0;
return temp;
}
T*
operator->() const
{
NS_PRECONDITION(mRawPtr != 0, "You can't dereference a NULL nsAutoArrayPtr with operator->().");
return get();
}
#ifdef CANT_RESOLVE_CPP_CONST_AMBIGUITY
// broken version for IRIX
nsAutoArrayPtr<T>*
get_address() const
// This is not intended to be used by clients. See |address_of|
// below.
{
return const_cast<nsAutoArrayPtr<T>*>(this);
}
#else // CANT_RESOLVE_CPP_CONST_AMBIGUITY
nsAutoArrayPtr<T>*
get_address()
// This is not intended to be used by clients. See |address_of|
// below.
{
return this;
}
const nsAutoArrayPtr<T>*
get_address() const
// This is not intended to be used by clients. See |address_of|
// below.
{
return this;
}
#endif // CANT_RESOLVE_CPP_CONST_AMBIGUITY
public:
T&
operator*() const
{
NS_PRECONDITION(mRawPtr != 0, "You can't dereference a NULL nsAutoArrayPtr with operator*().");
return *get();
}
T**
StartAssignment()
{
#ifndef NSCAP_FEATURE_INLINE_STARTASSIGNMENT
return reinterpret_cast<T**>(begin_assignment());
#else
assign(0);
return reinterpret_cast<T**>(&mRawPtr);
#endif
}
};
#ifdef CANT_RESOLVE_CPP_CONST_AMBIGUITY
// This is the broken version for IRIX, which can't handle the version below.
template <class T>
inline
nsAutoArrayPtr<T>*
address_of( const nsAutoArrayPtr<T>& aPtr )
{
return aPtr.get_address();
}
#else // CANT_RESOLVE_CPP_CONST_AMBIGUITY
template <class T>
inline
nsAutoArrayPtr<T>*
address_of( nsAutoArrayPtr<T>& aPtr )
{
return aPtr.get_address();
}
template <class T>
inline
const nsAutoArrayPtr<T>*
address_of( const nsAutoArrayPtr<T>& aPtr )
{
return aPtr.get_address();
}
#endif // CANT_RESOLVE_CPP_CONST_AMBIGUITY
template <class T>
class nsAutoArrayPtrGetterTransfers
/*
...
This class is designed to be used for anonymous temporary objects in the
argument list of calls that return COM interface pointers, e.g.,
nsAutoArrayPtr<IFoo> fooP;
...->GetTransferedPointer(getter_Transfers(fooP))
DO NOT USE THIS TYPE DIRECTLY IN YOUR CODE. Use |getter_Transfers()| instead.
When initialized with a |nsAutoArrayPtr|, as in the example above, it returns
a |void**|, a |T**|, or an |nsISupports**| as needed, that the
outer call (|GetTransferedPointer| in this case) can fill in.
This type should be a nested class inside |nsAutoArrayPtr<T>|.
*/
{
public:
explicit
nsAutoArrayPtrGetterTransfers( nsAutoArrayPtr<T>& aSmartPtr )
: mTargetSmartPtr(aSmartPtr)
{
// nothing else to do
}
operator void**()
{
return reinterpret_cast<void**>(mTargetSmartPtr.StartAssignment());
}
operator T**()
{
return mTargetSmartPtr.StartAssignment();
}
T*&
operator*()
{
return *(mTargetSmartPtr.StartAssignment());
}
private:
nsAutoArrayPtr<T>& mTargetSmartPtr;
};
template <class T>
inline
nsAutoArrayPtrGetterTransfers<T>
getter_Transfers( nsAutoArrayPtr<T>& aSmartPtr )
/*
Used around a |nsAutoArrayPtr| when
...makes the class |nsAutoArrayPtrGetterTransfers<T>| invisible.
*/
{
return nsAutoArrayPtrGetterTransfers<T>(aSmartPtr);
}
// Comparing two |nsAutoArrayPtr|s
template <class T, class U>
inline
NSCAP_BOOL
operator==( const nsAutoArrayPtr<T>& lhs, const nsAutoArrayPtr<U>& rhs )
{
return static_cast<const T*>(lhs.get()) == static_cast<const U*>(rhs.get());
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( const nsAutoArrayPtr<T>& lhs, const nsAutoArrayPtr<U>& rhs )
{
return static_cast<const T*>(lhs.get()) != static_cast<const U*>(rhs.get());
}
// Comparing an |nsAutoArrayPtr| to a raw pointer
template <class T, class U>
inline
NSCAP_BOOL
operator==( const nsAutoArrayPtr<T>& lhs, const U* rhs )
{
return static_cast<const T*>(lhs.get()) == static_cast<const U*>(rhs);
}
template <class T, class U>
inline
NSCAP_BOOL
operator==( const U* lhs, const nsAutoArrayPtr<T>& rhs )
{
return static_cast<const U*>(lhs) == static_cast<const T*>(rhs.get());
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( const nsAutoArrayPtr<T>& lhs, const U* rhs )
{
return static_cast<const T*>(lhs.get()) != static_cast<const U*>(rhs);
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( const U* lhs, const nsAutoArrayPtr<T>& rhs )
{
return static_cast<const U*>(lhs) != static_cast<const T*>(rhs.get());
}
// To avoid ambiguities caused by the presence of builtin |operator==|s
// creating a situation where one of the |operator==| defined above
// has a better conversion for one argument and the builtin has a
// better conversion for the other argument, define additional
// |operator==| without the |const| on the raw pointer.
// See bug 65664 for details.
#ifndef NSCAP_DONT_PROVIDE_NONCONST_OPEQ
template <class T, class U>
inline
NSCAP_BOOL
operator==( const nsAutoArrayPtr<T>& lhs, U* rhs )
{
return static_cast<const T*>(lhs.get()) == const_cast<const U*>(rhs);
}
template <class T, class U>
inline
NSCAP_BOOL
operator==( U* lhs, const nsAutoArrayPtr<T>& rhs )
{
return const_cast<const U*>(lhs) == static_cast<const T*>(rhs.get());
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( const nsAutoArrayPtr<T>& lhs, U* rhs )
{
return static_cast<const T*>(lhs.get()) != const_cast<const U*>(rhs);
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( U* lhs, const nsAutoArrayPtr<T>& rhs )
{
return const_cast<const U*>(lhs) != static_cast<const T*>(rhs.get());
}
#endif
// Comparing an |nsAutoArrayPtr| to |0|
template <class T>
inline
NSCAP_BOOL
operator==( const nsAutoArrayPtr<T>& lhs, NSCAP_Zero* rhs )
// specifically to allow |smartPtr == 0|
{
return static_cast<const void*>(lhs.get()) == reinterpret_cast<const void*>(rhs);
}
template <class T>
inline
NSCAP_BOOL
operator==( NSCAP_Zero* lhs, const nsAutoArrayPtr<T>& rhs )
// specifically to allow |0 == smartPtr|
{
return reinterpret_cast<const void*>(lhs) == static_cast<const void*>(rhs.get());
}
template <class T>
inline
NSCAP_BOOL
operator!=( const nsAutoArrayPtr<T>& lhs, NSCAP_Zero* rhs )
// specifically to allow |smartPtr != 0|
{
return static_cast<const void*>(lhs.get()) != reinterpret_cast<const void*>(rhs);
}
template <class T>
inline
NSCAP_BOOL
operator!=( NSCAP_Zero* lhs, const nsAutoArrayPtr<T>& rhs )
// specifically to allow |0 != smartPtr|
{
return reinterpret_cast<const void*>(lhs) != static_cast<const void*>(rhs.get());
}
#ifdef HAVE_CPP_TROUBLE_COMPARING_TO_ZERO
// We need to explicitly define comparison operators for `int'
// because the compiler is lame.
template <class T>
inline
NSCAP_BOOL
operator==( const nsAutoArrayPtr<T>& lhs, int rhs )
// specifically to allow |smartPtr == 0|
{
return static_cast<const void*>(lhs.get()) == reinterpret_cast<const void*>(rhs);
}
template <class T>
inline
NSCAP_BOOL
operator==( int lhs, const nsAutoArrayPtr<T>& rhs )
// specifically to allow |0 == smartPtr|
{
return reinterpret_cast<const void*>(lhs) == static_cast<const void*>(rhs.get());
}
#endif // !defined(HAVE_CPP_TROUBLE_COMPARING_TO_ZERO)
/*****************************************************************************/
// template <class T> class nsRefPtrGetterAddRefs;
template <class T>
class nsRefPtr
{
private:
void
assign_with_AddRef( T* rawPtr )
{
if ( rawPtr )
rawPtr->AddRef();
assign_assuming_AddRef(rawPtr);
}
void**
begin_assignment()
{
assign_assuming_AddRef(0);
return reinterpret_cast<void**>(&mRawPtr);
}
void
assign_assuming_AddRef( T* newPtr )
{
T* oldPtr = mRawPtr;
mRawPtr = newPtr;
if ( oldPtr )
oldPtr->Release();
}
private:
T* mRawPtr;
public:
typedef T element_type;
~nsRefPtr()
{
if ( mRawPtr )
mRawPtr->Release();
}
// Constructors
nsRefPtr()
: mRawPtr(0)
// default constructor
{
}
nsRefPtr( const nsRefPtr<T>& aSmartPtr )
: mRawPtr(aSmartPtr.mRawPtr)
// copy-constructor
{
if ( mRawPtr )
mRawPtr->AddRef();
}
nsRefPtr( T* aRawPtr )
: mRawPtr(aRawPtr)
// construct from a raw pointer (of the right type)
{
if ( mRawPtr )
mRawPtr->AddRef();
}
nsRefPtr( const already_AddRefed<T>& aSmartPtr )
: mRawPtr(aSmartPtr.mRawPtr)
// construct from |dont_AddRef(expr)|
{
}
// Assignment operators
nsRefPtr<T>&
operator=( const nsRefPtr<T>& rhs )
// copy assignment operator
{
assign_with_AddRef(rhs.mRawPtr);
return *this;
}
nsRefPtr<T>&
operator=( T* rhs )
// assign from a raw pointer (of the right type)
{
assign_with_AddRef(rhs);
return *this;
}
nsRefPtr<T>&
operator=( const already_AddRefed<T>& rhs )
// assign from |dont_AddRef(expr)|
{
assign_assuming_AddRef(rhs.mRawPtr);
return *this;
}
// Other pointer operators
void
swap( nsRefPtr<T>& rhs )
// ...exchange ownership with |rhs|; can save a pair of refcount operations
{
T* temp = rhs.mRawPtr;
rhs.mRawPtr = mRawPtr;
mRawPtr = temp;
}
void
swap( T*& rhs )
// ...exchange ownership with |rhs|; can save a pair of refcount operations
{
T* temp = rhs;
rhs = mRawPtr;
mRawPtr = temp;
}
already_AddRefed<T>
forget()
// return the value of mRawPtr and null out mRawPtr. Useful for
// already_AddRefed return values.
{
T* temp = 0;
swap(temp);
return temp;
}
template <typename I>
void
forget( I** rhs)
// Set the target of rhs to the value of mRawPtr and null out mRawPtr.
// Useful to avoid unnecessary AddRef/Release pairs with "out"
// parameters where rhs bay be a T** or an I** where I is a base class
// of T.
{
NS_ASSERTION(rhs, "Null pointer passed to forget!");
*rhs = mRawPtr;
mRawPtr = 0;
}
T*
get() const
/*
Prefer the implicit conversion provided automatically by |operator T*() const|.
Use |get()| to resolve ambiguity or to get a castable pointer.
*/
{
return const_cast<T*>(mRawPtr);
}
operator T*() const
/*
...makes an |nsRefPtr| act like its underlying raw pointer type whenever it
is used in a context where a raw pointer is expected. It is this operator
that makes an |nsRefPtr| substitutable for a raw pointer.
Prefer the implicit use of this operator to calling |get()|, except where
necessary to resolve ambiguity.
*/
{
return get();
}
T*
operator->() const
{
NS_PRECONDITION(mRawPtr != 0, "You can't dereference a NULL nsRefPtr with operator->().");
return get();
}
// This operator is needed for gcc <= 4.0.* and for Sun Studio; it
// causes internal compiler errors for some MSVC versions. (It's not
// clear to me whether it should be needed.)
#ifndef _MSC_VER
template <class U, class V>
U&
operator->*(U V::* aMember)
{
NS_PRECONDITION(mRawPtr != 0, "You can't dereference a NULL nsRefPtr with operator->*().");
return get()->*aMember;
}
#endif
#ifdef CANT_RESOLVE_CPP_CONST_AMBIGUITY
// broken version for IRIX
nsRefPtr<T>*
get_address() const
// This is not intended to be used by clients. See |address_of|
// below.
{
return const_cast<nsRefPtr<T>*>(this);
}
#else // CANT_RESOLVE_CPP_CONST_AMBIGUITY
nsRefPtr<T>*
get_address()
// This is not intended to be used by clients. See |address_of|
// below.
{
return this;
}
const nsRefPtr<T>*
get_address() const
// This is not intended to be used by clients. See |address_of|
// below.
{
return this;
}
#endif // CANT_RESOLVE_CPP_CONST_AMBIGUITY
public:
T&
operator*() const
{
NS_PRECONDITION(mRawPtr != 0, "You can't dereference a NULL nsRefPtr with operator*().");
return *get();
}
T**
StartAssignment()
{
#ifndef NSCAP_FEATURE_INLINE_STARTASSIGNMENT
return reinterpret_cast<T**>(begin_assignment());
#else
assign_assuming_AddRef(0);
return reinterpret_cast<T**>(&mRawPtr);
#endif
}
};
#ifdef CANT_RESOLVE_CPP_CONST_AMBIGUITY
// This is the broken version for IRIX, which can't handle the version below.
template <class T>
inline
nsRefPtr<T>*
address_of( const nsRefPtr<T>& aPtr )
{
return aPtr.get_address();
}
#else // CANT_RESOLVE_CPP_CONST_AMBIGUITY
template <class T>
inline
nsRefPtr<T>*
address_of( nsRefPtr<T>& aPtr )
{
return aPtr.get_address();
}
template <class T>
inline
const nsRefPtr<T>*
address_of( const nsRefPtr<T>& aPtr )
{
return aPtr.get_address();
}
#endif // CANT_RESOLVE_CPP_CONST_AMBIGUITY
template <class T>
class nsRefPtrGetterAddRefs
/*
...
This class is designed to be used for anonymous temporary objects in the
argument list of calls that return COM interface pointers, e.g.,
nsRefPtr<IFoo> fooP;
...->GetAddRefedPointer(getter_AddRefs(fooP))
DO NOT USE THIS TYPE DIRECTLY IN YOUR CODE. Use |getter_AddRefs()| instead.
When initialized with a |nsRefPtr|, as in the example above, it returns
a |void**|, a |T**|, or an |nsISupports**| as needed, that the
outer call (|GetAddRefedPointer| in this case) can fill in.
This type should be a nested class inside |nsRefPtr<T>|.
*/
{
public:
explicit
nsRefPtrGetterAddRefs( nsRefPtr<T>& aSmartPtr )
: mTargetSmartPtr(aSmartPtr)
{
// nothing else to do
}
operator void**()
{
return reinterpret_cast<void**>(mTargetSmartPtr.StartAssignment());
}
operator T**()
{
return mTargetSmartPtr.StartAssignment();
}
T*&
operator*()
{
return *(mTargetSmartPtr.StartAssignment());
}
private:
nsRefPtr<T>& mTargetSmartPtr;
};
template <class T>
inline
nsRefPtrGetterAddRefs<T>
getter_AddRefs( nsRefPtr<T>& aSmartPtr )
/*
Used around a |nsRefPtr| when
...makes the class |nsRefPtrGetterAddRefs<T>| invisible.
*/
{
return nsRefPtrGetterAddRefs<T>(aSmartPtr);
}
// Comparing two |nsRefPtr|s
template <class T, class U>
inline
NSCAP_BOOL
operator==( const nsRefPtr<T>& lhs, const nsRefPtr<U>& rhs )
{
return static_cast<const T*>(lhs.get()) == static_cast<const U*>(rhs.get());
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( const nsRefPtr<T>& lhs, const nsRefPtr<U>& rhs )
{
return static_cast<const T*>(lhs.get()) != static_cast<const U*>(rhs.get());
}
// Comparing an |nsRefPtr| to a raw pointer
template <class T, class U>
inline
NSCAP_BOOL
operator==( const nsRefPtr<T>& lhs, const U* rhs )
{
return static_cast<const T*>(lhs.get()) == static_cast<const U*>(rhs);
}
template <class T, class U>
inline
NSCAP_BOOL
operator==( const U* lhs, const nsRefPtr<T>& rhs )
{
return static_cast<const U*>(lhs) == static_cast<const T*>(rhs.get());
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( const nsRefPtr<T>& lhs, const U* rhs )
{
return static_cast<const T*>(lhs.get()) != static_cast<const U*>(rhs);
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( const U* lhs, const nsRefPtr<T>& rhs )
{
return static_cast<const U*>(lhs) != static_cast<const T*>(rhs.get());
}
// To avoid ambiguities caused by the presence of builtin |operator==|s
// creating a situation where one of the |operator==| defined above
// has a better conversion for one argument and the builtin has a
// better conversion for the other argument, define additional
// |operator==| without the |const| on the raw pointer.
// See bug 65664 for details.
#ifndef NSCAP_DONT_PROVIDE_NONCONST_OPEQ
template <class T, class U>
inline
NSCAP_BOOL
operator==( const nsRefPtr<T>& lhs, U* rhs )
{
return static_cast<const T*>(lhs.get()) == const_cast<const U*>(rhs);
}
template <class T, class U>
inline
NSCAP_BOOL
operator==( U* lhs, const nsRefPtr<T>& rhs )
{
return const_cast<const U*>(lhs) == static_cast<const T*>(rhs.get());
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( const nsRefPtr<T>& lhs, U* rhs )
{
return static_cast<const T*>(lhs.get()) != const_cast<const U*>(rhs);
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( U* lhs, const nsRefPtr<T>& rhs )
{
return const_cast<const U*>(lhs) != static_cast<const T*>(rhs.get());
}
#endif
// Comparing an |nsRefPtr| to |0|
template <class T>
inline
NSCAP_BOOL
operator==( const nsRefPtr<T>& lhs, NSCAP_Zero* rhs )
// specifically to allow |smartPtr == 0|
{
return static_cast<const void*>(lhs.get()) == reinterpret_cast<const void*>(rhs);
}
template <class T>
inline
NSCAP_BOOL
operator==( NSCAP_Zero* lhs, const nsRefPtr<T>& rhs )
// specifically to allow |0 == smartPtr|
{
return reinterpret_cast<const void*>(lhs) == static_cast<const void*>(rhs.get());
}
template <class T>
inline
NSCAP_BOOL
operator!=( const nsRefPtr<T>& lhs, NSCAP_Zero* rhs )
// specifically to allow |smartPtr != 0|
{
return static_cast<const void*>(lhs.get()) != reinterpret_cast<const void*>(rhs);
}
template <class T>
inline
NSCAP_BOOL
operator!=( NSCAP_Zero* lhs, const nsRefPtr<T>& rhs )
// specifically to allow |0 != smartPtr|
{
return reinterpret_cast<const void*>(lhs) != static_cast<const void*>(rhs.get());
}
#ifdef HAVE_CPP_TROUBLE_COMPARING_TO_ZERO
// We need to explicitly define comparison operators for `int'
// because the compiler is lame.
template <class T>
inline
NSCAP_BOOL
operator==( const nsRefPtr<T>& lhs, int rhs )
// specifically to allow |smartPtr == 0|
{
return static_cast<const void*>(lhs.get()) == reinterpret_cast<const void*>(rhs);
}
template <class T>
inline
NSCAP_BOOL
operator==( int lhs, const nsRefPtr<T>& rhs )
// specifically to allow |0 == smartPtr|
{
return reinterpret_cast<const void*>(lhs) == static_cast<const void*>(rhs.get());
}
#endif // !defined(HAVE_CPP_TROUBLE_COMPARING_TO_ZERO)
/*****************************************************************************/
#endif // !defined(nsAutoPtr_h___)
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