pjs/xpcom/base/nsCOMPtr.h

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C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/*
* The contents of this file are subject to the Netscape 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/NPL/
*
* 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 Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
* Scott Collins <scc@netscape.com>
*/
#ifndef nsCOMPtr_h___
#define nsCOMPtr_h___
/*
Having problems?
See the User Manual at:
<http://www.mozilla.org/projects/xpcom/nsCOMPtr.html>
*/
// Wrapping includes can speed up compiles (see "Large Scale C++ Software Design")
#ifndef nsDebug_h___
#include "nsDebug.h"
// for |NS_PRECONDITION|
#endif
#ifndef nsISupports_h___
#include "nsISupports.h"
// for |nsresult|, |NS_ADDREF|, |NS_GET_IID| et al
#endif
#ifndef nscore_h__
#include "nscore.h"
// for |NS_..._CAST|, |NS_EXPORT|
#endif
/*
WARNING:
This file defines several macros for internal use only. These macros begin with the
prefix |NSCAP_|. Do not use these macros in your own code. They are for internal use
only for cross-platform compatibility, and are subject to change without notice.
*/
/*
Set up some |#define|s to turn off a couple of troublesome C++ features.
Interestingly, none of the compilers barf on template stuff. These are set up automatically
by the autoconf system for all Unixes. (Temporarily, I hope) I have to define them
myself for Mac and Windows.
*/
// under Metrowerks (Mac), we don't have autoconf yet
#ifdef __MWERKS__
#define HAVE_CPP_USING
#define HAVE_CPP_EXPLICIT
#define HAVE_CPP_BOOL
#endif
// under VC++ (Windows), we don't have autoconf yet
#ifdef _MSC_VER
#define HAVE_CPP_EXPLICIT
#define HAVE_CPP_USING
#if (_MSC_VER<1100)
// before 5.0, VC++ couldn't handle explicit
#undef HAVE_CPP_EXPLICIT
#elif (_MSC_VER==1100)
// VC++5.0 has an internal compiler error (sometimes) without this
#undef HAVE_CPP_USING
#endif
#define NSCAP_FEATURE_INLINE_STARTASSIGNMENT
// under VC++, we win by inlining StartAssignment
// Also under VC++, at the highest warning level, we are overwhelmed with warnings
// about (unused) inline functions being removed. This is to be expected with
// templates, so we disable the warning.
#pragma warning( disable: 4514 )
#endif
#define NSCAP_FEATURE_FACTOR_DESTRUCTOR
#ifdef NS_DEBUG
#define NSCAP_FEATURE_TEST_DONTQUERY_CASES
#define NSCAP_FEATURE_DEBUG_PTR_TYPES
#endif
/*
|...TEST_DONTQUERY_CASES| and |...DEBUG_PTR_TYPES| introduce some code that is
problematic on a select few of our platforms, e.g., QNX. Therefore, I'm providing
a mechanism by which these features can be explicitly disabled from the command-line.
*/
#ifdef NSCAP_DISABLE_TEST_DONTQUERY_CASES
#undef NSCAP_FEATURE_TEST_DONTQUERY_CASES
#endif
#if defined(NSCAP_DISABLE_DEBUG_PTR_TYPES) || !defined(NS_DEBUG)
#undef NSCAP_FEATURE_DEBUG_PTR_TYPES
#endif
#ifdef NSCAP_FEATURE_DEBUG_PTR_TYPES
#undef NSCAP_FEATURE_FACTOR_DESTRUCTOR
#endif
/*
If the compiler doesn't support |explicit|, we'll just make it go away, trusting
that the builds under compilers that do have it will keep us on the straight and narrow.
*/
#ifndef HAVE_CPP_EXPLICIT
#define explicit
#endif
#ifdef HAVE_CPP_BOOL
typedef bool NSCAP_BOOL;
#else
typedef PRBool NSCAP_BOOL;
#endif
#ifdef NSCAP_FEATURE_DEBUG_MACROS
#define NSCAP_ADDREF(ptr) NS_ADDREF(ptr)
#define NSCAP_RELEASE(ptr) NS_RELEASE(ptr)
#else
#define NSCAP_ADDREF(ptr) (ptr)->AddRef()
#define NSCAP_RELEASE(ptr) (ptr)->Release()
#endif
/*
WARNING:
VC++4.2 is very picky. To compile under VC++4.2, the classes must be defined
in an order that satisfies:
nsDerivedSafe < nsCOMPtr
nsDontAddRef < nsCOMPtr
nsCOMPtr < nsGetterAddRefs
The other compilers probably won't complain, so please don't reorder these
classes, on pain of breaking 4.2 compatibility.
*/
template <class T>
class nsDerivedSafe : public T
/*
No client should ever see or have to type the name of this class. It is the
artifact that makes it a compile-time error to call |AddRef| and |Release|
on a |nsCOMPtr|. DO NOT USE THIS TYPE DIRECTLY IN YOUR CODE.
See |nsCOMPtr::operator->|, |nsCOMPtr::operator*|, et al.
This type should be a nested class inside |nsCOMPtr<T>|.
*/
{
private:
#ifdef HAVE_CPP_USING
using T::AddRef;
using T::Release;
#else
NS_IMETHOD_(nsrefcnt) AddRef(void);
NS_IMETHOD_(nsrefcnt) Release(void);
#endif
void operator delete( void*, size_t ); // NOT TO BE IMPLEMENTED
// declaring |operator delete| private makes calling delete on an interface pointer a compile error
nsDerivedSafe<T>& operator=( const T& ); // NOT TO BE IMPLEMENTED
// you may not call |operator=()| through a dereferenced |nsCOMPtr|, because you'd get the wrong one
/*
Compiler warnings and errors: nsDerivedSafe operator=() hides inherited operator=().
If you see that, that means somebody checked in a (XP)COM interface class that declares an
|operator=()|, and that's _bad_. So bad, in fact, that this declaration exists explicitly
to stop people from doing it.
*/
};
#if !defined(HAVE_CPP_USING) && defined(NEED_CPP_UNUSED_IMPLEMENTATIONS)
template <class T>
nsrefcnt
nsDerivedSafe<T>::AddRef()
{
return 0;
}
template <class T>
nsrefcnt
nsDerivedSafe<T>::Release()
{
return 0;
}
#endif
/*
There used to be machinery to allow |dont_QueryInterface()| to work, but
since it is now equivalent to using a raw pointer ... all that machinery
has gone away. For pointer arguments, the following definition should
optimize away. This is better than using a |#define| because it is
scoped.
*/
template <class T>
inline
T*
dont_QueryInterface( T* expr )
{
return expr;
}
class nsCOMPtr_helper
/*
An |nsCOMPtr_helper| transforms commonly called getters into typesafe forms
that are more convenient to call, and more efficient to use with |nsCOMPtr|s.
Good candidates for helpers are |QueryInterface()|, |CreateInstance()|, etc.
Here are the rules for a helper:
- it implements operator() to produce an interface pointer
- (except for its name) operator() is a valid [XP]COM `getter'
- that interface pointer it returns is already |AddRef()|ed (as from any good getter)
- it matches the type requested with the supplied |nsIID| argument
- its constructor provides an optional |nsresult*| that |operator()| can fill
in with an error when it is executed
See |class nsQueryInterface| for an example.
*/
{
public:
virtual nsresult operator()( const nsIID&, void** ) const = 0;
};
class NS_EXPORT nsQueryInterface : public nsCOMPtr_helper
{
public:
nsQueryInterface( nsISupports* aRawPtr, nsresult* error )
: mRawPtr(aRawPtr),
mErrorPtr(error)
{
// nothing else to do here
}
virtual nsresult operator()( const nsIID& aIID, void** ) const;
private:
nsISupports* mRawPtr;
nsresult* mErrorPtr;
};
inline
const nsQueryInterface
do_QueryInterface( nsISupports* aRawPtr, nsresult* error = 0 )
{
return nsQueryInterface(aRawPtr, error);
}
/**
* |null_nsCOMPtr| is deprecated. Please use the value |0| instead.
* |#define|s are bad, because they aren't scoped. But I can't replace
* this definition with an inline, because only a compile-time |0| gets
* magically converted to arbitrary pointer types. This doesn't automatically
* happen for just any |const int| with the value |0|.
*
* Ergo: we really want to eliminate all uses of |null_nsCOMPtr()| in favor of
* |0|.
*/
#define null_nsCOMPtr() (0)
template <class T>
struct nsDontAddRef
/*
...cooperates with |nsCOMPtr| to allow you to assign in a pointer _without_
|AddRef|ing it. You would rarely use this directly, but rather through the
machinery of |getter_AddRefs| in the argument list to functions that |AddRef|
their results before returning them to the caller.
DO NOT USE THIS TYPE DIRECTLY IN YOUR CODE. Use |getter_AddRefs()| or
|dont_AddRef()| instead.
See also |getter_AddRefs()|, |dont_AddRef()|, and |class nsGetterAddRefs|.
This type should be a nested class inside |nsCOMPtr<T>|.
Yes, |nsDontAddRef| could have been implemented as an |nsCOMPtr_helper| to
avoid adding specialized machinery to |nsCOMPtr| ... but this is the simplest
case, and perhaps worth the savings in time and space that its specific
implementation affords over the more general solution offered by
|nsCOMPtr_helper|.
*/
{
explicit
nsDontAddRef( T* aRawPtr )
: mRawPtr(aRawPtr)
{
// nothing else to do here
}
T* mRawPtr;
};
template <class T>
inline
const nsDontAddRef<T>
getter_AddRefs( T* aRawPtr )
/*
...makes typing easier, because it deduces the template type, e.g.,
you write |dont_AddRef(fooP)| instead of |nsDontAddRef<IFoo>(fooP)|.
*/
{
return nsDontAddRef<T>(aRawPtr);
}
template <class T>
inline
const nsDontAddRef<T>
dont_AddRef( T* aRawPtr )
{
return nsDontAddRef<T>(aRawPtr);
}
class nsCOMPtr_base
/*
...factors implementation for all template versions of |nsCOMPtr|.
This should really be an |nsCOMPtr<nsISupports>|, but this wouldn't work
because unlike the
Here's the way people normally do things like this
template <class T> class Foo { ... };
template <> class Foo<void*> { ... };
template <class T> class Foo<T*> : private Foo<void*> { ... };
*/
{
public:
nsCOMPtr_base( nsISupports* rawPtr = 0 )
: mRawPtr(rawPtr)
{
// nothing else to do here
}
#ifdef NSCAP_FEATURE_FACTOR_DESTRUCTOR
NS_EXPORT ~nsCOMPtr_base();
#endif
NS_EXPORT void assign_with_AddRef( nsISupports* );
NS_EXPORT void assign_from_helper( const nsCOMPtr_helper&, const nsIID& );
NS_EXPORT void** begin_assignment();
protected:
nsISupports* mRawPtr;
void
assign_assuming_AddRef( nsISupports* newPtr )
{
/*
|AddRef()|ing the new value (before entering this function) before
|Release()|ing the old lets us safely ignore the self-assignment case.
We must, however, be careful only to |Release()| _after_ doing the
assignment, in case the |Release()| leads to our _own_ destruction,
which would, in turn, cause an incorrect second |Release()| of our old
pointer. Thank waterson@netscape.com for discovering this.
*/
nsISupports* oldPtr = mRawPtr;
mRawPtr = newPtr;
if ( oldPtr )
NSCAP_RELEASE(oldPtr);
}
};
// template <class T> class nsGetterAddRefs;
template <class T>
class nsCOMPtr
#ifndef NSCAP_FEATURE_DEBUG_PTR_TYPES
: private nsCOMPtr_base
#endif
{
#ifdef NSCAP_FEATURE_DEBUG_PTR_TYPES
private:
void assign_with_AddRef( nsISupports* );
void assign_from_helper( const nsCOMPtr_helper&, const nsIID& );
void** begin_assignment();
void
assign_assuming_AddRef( T* newPtr )
{
T* oldPtr = mRawPtr;
mRawPtr = newPtr;
if ( oldPtr )
NSCAP_RELEASE(oldPtr);
}
private:
T* mRawPtr;
#define NSCAP_CTOR_BASE(x) mRawPtr(x)
#else
#define NSCAP_CTOR_BASE(x) nsCOMPtr_base(x)
#endif
public:
typedef T element_type;
#ifndef NSCAP_FEATURE_FACTOR_DESTRUCTOR
~nsCOMPtr()
{
if ( mRawPtr )
NSCAP_RELEASE(mRawPtr);
}
#endif
#ifdef NSCAP_FEATURE_TEST_DONTQUERY_CASES
void
Assert_NoQueryNeeded()
{
if ( mRawPtr )
{
T* query_result = 0;
nsresult status = CallQueryInterface(mRawPtr, &query_result);
NS_ASSERTION(query_result == mRawPtr, "QueryInterface needed");
if ( NS_SUCCEEDED(status) )
NSCAP_RELEASE(query_result);
}
}
#define NSCAP_ASSERT_NO_QUERY_NEEDED(); Assert_NoQueryNeeded();
#else
#define NSCAP_ASSERT_NO_QUERY_NEEDED();
#endif
// Constructors
nsCOMPtr()
: NSCAP_CTOR_BASE(0)
// default constructor
{
// nothing else to do here
}
nsCOMPtr( const nsCOMPtr<T>& aSmartPtr )
: NSCAP_CTOR_BASE(aSmartPtr.mRawPtr)
// copy-constructor
{
if ( mRawPtr )
NSCAP_ADDREF(mRawPtr);
}
nsCOMPtr( T* aRawPtr )
: NSCAP_CTOR_BASE(aRawPtr)
// construct from a raw pointer (of the right type)
{
if ( mRawPtr )
NSCAP_ADDREF(mRawPtr);
NSCAP_ASSERT_NO_QUERY_NEEDED();
}
nsCOMPtr( const nsDontAddRef<T>& aSmartPtr )
: NSCAP_CTOR_BASE(aSmartPtr.mRawPtr)
// construct from |dont_AddRef(expr)|
{
NSCAP_ASSERT_NO_QUERY_NEEDED();
}
nsCOMPtr( const nsCOMPtr_helper& helper )
: NSCAP_CTOR_BASE(0)
// ...and finally, anything else we might need to construct from
// can exploit the |nsCOMPtr_helper| facility
{
assign_from_helper(helper, NS_GET_IID(T));
NSCAP_ASSERT_NO_QUERY_NEEDED();
}
// Assignment operators
nsCOMPtr<T>&
operator=( const nsCOMPtr<T>& rhs )
// copy assignment operator
{
assign_with_AddRef(rhs.mRawPtr);
return *this;
}
nsCOMPtr<T>&
operator=( T* rhs )
// assign from a raw pointer (of the right type)
{
assign_with_AddRef(rhs);
NSCAP_ASSERT_NO_QUERY_NEEDED();
return *this;
}
nsCOMPtr<T>&
operator=( const nsDontAddRef<T>& rhs )
// assign from |dont_AddRef(expr)|
{
assign_assuming_AddRef(rhs.mRawPtr);
NSCAP_ASSERT_NO_QUERY_NEEDED();
return *this;
}
nsCOMPtr<T>&
operator=( const nsCOMPtr_helper& rhs )
// ...and finally, anything else we might need to assign from
// can exploit the |nsCOMPtr_helper| facility.
{
assign_from_helper(rhs, NS_GET_IID(T));
NSCAP_ASSERT_NO_QUERY_NEEDED();
return *this;
}
// Other pointer operators
nsDerivedSafe<T>*
get() const
/*
Prefer the implicit conversion provided automatically by |operator nsDerivedSafe<nsISupports*() const|.
Use |get()| _only_ to resolve ambiguity.
Returns a |nsDerivedSafe<T>*| to deny clients the use of |AddRef| and |Release|.
*/
{
return NS_REINTERPRET_CAST(nsDerivedSafe<T>*, mRawPtr);
}
operator nsDerivedSafe<T>*() const
/*
...makes an |nsCOMPtr| act like its underlying raw pointer type (except against |AddRef()|, |Release()|,
and |delete|) whenever it is used in a context where a raw pointer is expected. It is this operator
that makes an |nsCOMPtr| substitutable for a raw pointer.
Prefer the implicit use of this operator to calling |get()|, except where necessary to resolve ambiguity.
*/
{
return get();
}
nsDerivedSafe<T>*
operator->() const
{
NS_PRECONDITION(mRawPtr != 0, "You can't dereference a NULL nsCOMPtr with operator->().");
return get();
}
nsDerivedSafe<T>&
operator*() const
{
NS_PRECONDITION(mRawPtr != 0, "You can't dereference a NULL nsCOMPtr with operator*().");
return *get();
}
#if 0
private:
friend class nsGetterAddRefs<T>;
#endif
T**
StartAssignment()
{
#ifndef NSCAP_FEATURE_INLINE_STARTASSIGNMENT
return NS_REINTERPRET_CAST(T**, begin_assignment());
#else
assign_assuming_AddRef(0);
return NS_REINTERPRET_CAST(T**, &mRawPtr);
#endif
}
};
/*
Specializing |nsCOMPtr| for |nsISupports| allows us to
*/
// template <>
class nsCOMPtr<nsISupports>
: private nsCOMPtr_base
{
public:
typedef nsISupports element_type;
#ifndef NSCAP_FEATURE_FACTOR_DESTRUCTOR
~nsCOMPtr()
{
if ( mRawPtr )
NSCAP_RELEASE(mRawPtr);
}
#endif
// Constructors
nsCOMPtr()
: nsCOMPtr_base(0)
// default constructor
{
// nothing else to do here
}
nsCOMPtr( const nsCOMPtr<nsISupports>& aSmartPtr )
: nsCOMPtr_base(aSmartPtr.mRawPtr)
// copy constructor
{
if ( mRawPtr )
NSCAP_ADDREF(mRawPtr);
}
nsCOMPtr( nsISupports* aRawPtr )
: nsCOMPtr_base(aRawPtr)
// construct from a raw pointer (of the right type)
{
if ( mRawPtr )
NSCAP_ADDREF(mRawPtr);
}
nsCOMPtr( const nsDontAddRef<nsISupports>& aSmartPtr )
: nsCOMPtr_base(aSmartPtr.mRawPtr)
// construct from |dont_AddRef(expr)|
{
// nothing else to do here
}
nsCOMPtr( const nsCOMPtr_helper& helper )
: nsCOMPtr_base(0)
// ...and finally, anything else we might need to construct from
// can exploit the |nsCOMPtr_helper| facility
{
assign_from_helper(helper, NS_GET_IID(nsISupports));
}
// Assignment operators
nsCOMPtr<nsISupports>&
operator=( const nsCOMPtr<nsISupports>& rhs )
// copy assignment operator
{
assign_with_AddRef(rhs.mRawPtr);
return *this;
}
nsCOMPtr<nsISupports>&
operator=( nsISupports* rhs )
// assign from a raw pointer (of the right type)
{
assign_with_AddRef(rhs);
return *this;
}
nsCOMPtr<nsISupports>&
operator=( const nsDontAddRef<nsISupports>& rhs )
// assign from |dont_AddRef(expr)|
{
assign_assuming_AddRef(rhs.mRawPtr);
return *this;
}
nsCOMPtr<nsISupports>&
operator=( const nsCOMPtr_helper& rhs )
// ...and finally, anything else we might need to assign from
// can exploit the |nsCOMPtr_helper| facility.
{
assign_from_helper(rhs, NS_GET_IID(nsISupports));
return *this;
}
// Other pointer operators
nsDerivedSafe<nsISupports>*
get() const
/*
Prefer the implicit conversion provided automatically by |operator nsDerivedSafe<nsISupports*() const|.
Use |get()| _only_ to resolve ambiguity.
Returns a |nsDerivedSafe<T>*| to deny clients the use of |AddRef| and |Release|.
*/
{
return NS_REINTERPRET_CAST(nsDerivedSafe<nsISupports>*, mRawPtr);
}
operator nsDerivedSafe<nsISupports>*() const
/*
...makes an |nsCOMPtr| act like its underlying raw pointer type (except against |AddRef()|, |Release()|,
and |delete|) whenever it is used in a context where a raw pointer is expected. It is this operator
that makes an |nsCOMPtr| substitutable for a raw pointer.
Prefer the implicit use of this operator to calling |get()|, except where necessary to resolve ambiguity.
*/
{
return get();
}
nsDerivedSafe<nsISupports>*
operator->() const
{
NS_PRECONDITION(mRawPtr != 0, "You can't dereference a NULL nsCOMPtr with operator->().");
return get();
}
nsDerivedSafe<nsISupports>&
operator*() const
{
NS_PRECONDITION(mRawPtr != 0, "You can't dereference a NULL nsCOMPtr with operator*().");
return *get();
}
#if 0
private:
friend class nsGetterAddRefs<nsISupports>;
#endif
nsISupports**
StartAssignment()
{
#ifndef NSCAP_FEATURE_INLINE_STARTASSIGNMENT
return NS_REINTERPRET_CAST(nsISupports**, begin_assignment());
#else
assign_assuming_AddRef(0);
return NS_REINTERPRET_CAST(nsISupports**, &mRawPtr);
#endif
}
};
#ifdef NSCAP_FEATURE_DEBUG_PTR_TYPES
template <class T>
void
nsCOMPtr<T>::assign_with_AddRef( nsISupports* rawPtr )
{
if ( rawPtr )
NSCAP_ADDREF(rawPtr);
assign_assuming_AddRef(NS_REINTERPRET_CAST(T*, rawPtr));
}
template <class T>
void
nsCOMPtr<T>::assign_from_helper( const nsCOMPtr_helper& helper, const nsIID& aIID )
{
T* newRawPtr;
if ( !NS_SUCCEEDED( helper(aIID, NS_REINTERPRET_CAST(void**, &newRawPtr)) ) )
newRawPtr = 0;
assign_assuming_AddRef(newRawPtr);
}
template <class T>
void**
nsCOMPtr<T>::begin_assignment()
{
assign_assuming_AddRef(0);
return NS_REINTERPRET_CAST(void**, &mRawPtr);
}
#endif
template <class T>
class nsGetterAddRefs
/*
...
This class is designed to be used for anonymous temporary objects in the
argument list of calls that return COM interface pointers, e.g.,
nsCOMPtr<IFoo> fooP;
...->QueryInterface(iid, getter_AddRefs(fooP))
DO NOT USE THIS TYPE DIRECTLY IN YOUR CODE. Use |getter_AddRefs()| instead.
When initialized with a |nsCOMPtr|, as in the example above, it returns
a |void**| (or |T**| if needed) that the outer call (|QueryInterface| in this
case) can fill in.
This type should be a nested class inside |nsCOMPtr<T>|.
*/
{
public:
explicit
nsGetterAddRefs( nsCOMPtr<T>& aSmartPtr )
: mTargetSmartPtr(aSmartPtr)
{
// nothing else to do
}
#if 0
#ifdef NSCAP_FEATURE_TEST_DONTQUERY_CASES
~nsGetterAddRefs()
{
mTargetSmartPtr.Assert_NoQueryNeeded();
}
#endif
#endif
operator void**()
{
return NS_REINTERPRET_CAST(void**, mTargetSmartPtr.StartAssignment());
}
operator T**()
{
return mTargetSmartPtr.StartAssignment();
}
operator nsISupports**()
{
return NS_REINTERPRET_CAST(nsISupports**, mTargetSmartPtr.StartAssignment());
}
T*&
operator*()
{
return *(mTargetSmartPtr.StartAssignment());
}
private:
nsCOMPtr<T>& mTargetSmartPtr;
};
// template <>
class nsGetterAddRefs<nsISupports>
{
public:
explicit
nsGetterAddRefs( nsCOMPtr<nsISupports>& aSmartPtr )
: mTargetSmartPtr(aSmartPtr)
{
// nothing else to do
}
operator void**()
{
return NS_REINTERPRET_CAST(void**, mTargetSmartPtr.StartAssignment());
}
operator nsISupports**()
{
return mTargetSmartPtr.StartAssignment();
}
nsISupports*&
operator*()
{
return *(mTargetSmartPtr.StartAssignment());
}
private:
nsCOMPtr<nsISupports>& mTargetSmartPtr;
};
template <class T>
inline
nsGetterAddRefs<T>
getter_AddRefs( nsCOMPtr<T>& aSmartPtr )
/*
Used around a |nsCOMPtr| when
...makes the class |nsGetterAddRefs<T>| invisible.
*/
{
return nsGetterAddRefs<T>(aSmartPtr);
}
class NSCAP_Zero;
template <class T, class U>
inline
NSCAP_BOOL
operator==( const nsCOMPtr<T>& lhs, const nsCOMPtr<U>& rhs )
{
return NS_STATIC_CAST(const void*, lhs.get()) == NS_STATIC_CAST(const void*, rhs.get());
}
template <class T, class U>
inline
NSCAP_BOOL
operator==( const nsCOMPtr<T>& lhs, const U* rhs )
{
return NS_STATIC_CAST(const void*, lhs.get()) == NS_STATIC_CAST(const void*, rhs);
}
template <class T, class U>
inline
NSCAP_BOOL
operator==( const U* lhs, const nsCOMPtr<T>& rhs )
{
return NS_STATIC_CAST(const void*, lhs) == NS_STATIC_CAST(const void*, rhs.get());
}
template <class T>
inline
NSCAP_BOOL
operator==( const nsCOMPtr<T>& lhs, NSCAP_Zero* rhs )
// specifically to allow |smartPtr == 0|
{
return NS_STATIC_CAST(const void*, lhs.get()) == NS_REINTERPRET_CAST(const void*, rhs);
}
template <class T>
inline
NSCAP_BOOL
operator==( NSCAP_Zero* lhs, const nsCOMPtr<T>& rhs )
// specifically to allow |0 == smartPtr|
{
return NS_REINTERPRET_CAST(const void*, lhs) == NS_STATIC_CAST(const void*, rhs.get());
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( const nsCOMPtr<T>& lhs, const nsCOMPtr<U>& rhs )
{
return NS_STATIC_CAST(const void*, lhs.get()) != NS_STATIC_CAST(const void*, rhs.get());
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( const nsCOMPtr<T>& lhs, const U* rhs )
{
return NS_STATIC_CAST(const void*, lhs.get()) != NS_STATIC_CAST(const void*, rhs);
}
template <class T, class U>
inline
NSCAP_BOOL
operator!=( const U* lhs, const nsCOMPtr<T>& rhs )
{
return NS_STATIC_CAST(const void*, lhs) != NS_STATIC_CAST(const void*, rhs.get());
}
template <class T>
inline
NSCAP_BOOL
operator!=( const nsCOMPtr<T>& lhs, NSCAP_Zero* rhs )
// specifically to allow |smartPtr != 0|
{
return NS_STATIC_CAST(const void*, lhs.get()) != NS_REINTERPRET_CAST(const void*, rhs);
}
template <class T>
inline
NSCAP_BOOL
operator!=( NSCAP_Zero* lhs, const nsCOMPtr<T>& rhs )
// specifically to allow |0 != smartPtr|
{
return NS_REINTERPRET_CAST(const void*, lhs) != NS_STATIC_CAST(const void*, rhs.get());
}
inline
NSCAP_BOOL
SameCOMIdentity( nsISupports* lhs, nsISupports* rhs )
{
return nsCOMPtr<nsISupports>( do_QueryInterface(lhs) ) == nsCOMPtr<nsISupports>( do_QueryInterface(rhs) );
}
template <class T>
inline
nsresult
CallQueryInterface( nsCOMPtr<T>& aSourcePtr, T** aDestPtr )
{
return CallQueryInterface(aSourcePtr.get(), aDestPtr);
}
#endif // !defined(nsCOMPtr_h___)