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/****************************************************************************
** Copyright (C) 2001-2010 Klaralvdalens Datakonsult AB. All rights reserved.
**
** This file is part of the KD Tools library.
**
** Licensees holding valid commercial KD Tools licenses may use this file in
** accordance with the KD Tools Commercial License Agreement provided with
** the Software.
**
**
** This file may be distributed and/or modified under the terms of the
** GNU Lesser General Public License version 2 and version 3 as published by the
** Free Software Foundation and appearing in the file LICENSE.LGPL included.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
** Contact info@kdab.com if any conditions of this licensing are not
** clear to you.
**
**********************************************************************/
#include "pimpl_ptr.h"
/*!
\class pimpl_ptr:
\ingroup core smartptr
\brief Owning pointer for private implementations
\since_c 2.1
(The exception safety of this class has not been evaluated yet.)
pimpl_ptr is a smart immutable pointer, which owns the contained object. Unlike other smart pointers,
it creates a standard constructed object when instanciated via the
\link pimpl_ptr() standard constructor\endlink.
Additionally, pimpl_ptr respects constness of the pointer object and returns \c const \c T* for
a const pimpl_ptr object.
The content of a pimpl_ptr cannot be changed during it's lifetime.
\section general-use General Use
The general use case of pimpl_ptr is the "Pimpl Idiom", i.e. hiding the private implementation of a class
from the user's compiler which see \c MyClass as
\code
class MyClass
{
public:
MyClass();
~MyClass();
// public class API
int value() const;
private:
class Private; // defined later
kdtools::pimpl_ptr< Private > d;
};
\endcode
but not the private parts of it. These can only be seen (and accessed) by the code knowing \c MyClass::Private:
\code
class MyClass::Private
{
public:
int value;
};
MyClass::MyClass()
{
// d was automatically filled with new Private
d->value = 42;
}
MyClass::~MyClass()
{
// the content of d gets deleted automatically
}
int MyClass::value() const
{
// access the private part:
// since MyClass::value() is const, the returned pointee is const, too
return d->value;
}
\endcode
*/
/*!
\fn pimpl_ptr::pimpl_ptr()
Default constructor. Constructs a pimpl_tr that contains (owns) a standard constructed
instance of \c T.
\post \c *this owns a new object.
*/
/*!
\fn pimpl_ptr::pimpl_ptr( T * t )
Constructor. Constructs a pimpl_ptr that contains (owns) \a t.
\post get() == obj
*/
/*!
\fn pimpl_ptr::~pimpl_ptr()
Destructor.
\post The object previously owned by \c *this has been deleted.
*/
/*!
\fn const T * pimpl_ptr::get() const
\returns a const pointer to the contained (owned) object.
\overload
*/
/*!
\fn T * pimpl_ptr::get()
\returns a pointer to the contained (owned) object.
*/
/*!
\fn const T & pimpl_ptr::operator*() const
Dereference operator. Returns \link get() *get()\endlink.
\overload
*/
/*!
\fn T & pimpl_ptr::operator*()
Dereference operator. Returns \link get() *get()\endlink.
*/
/*!
\fn const T * pimpl_ptr::operator->() const
Member-by-pointer operator. Returns get().
\overload
*/
/*!
\fn T * pimpl_ptr::operator->()
Member-by-pointer operator. Returns get().
*/
#ifdef KDTOOLSCORE_UNITTESTS
#include <KDUnitTest/test.h>
#include <QObject>
#include <QPointer>
namespace
{
struct ConstTester
{
bool isConst()
{
return false;
}
bool isConst() const
{
return true;
}
};
}
KDAB_UNITTEST_SIMPLE( pimpl_ptr, "kdcoretools" ) {
{
kdtools::pimpl_ptr< QObject > p;
assertNotNull( p.get() );
assertNull( p->parent() );
}
{
QPointer< QObject > o;
{
kdtools::pimpl_ptr< QObject > qobject( new QObject );
o = qobject.get();
assertEqual( o, qobject.operator->() );
assertEqual( o, &(qobject.operator*()) );
}
assertNull( o );
}
{
const kdtools::pimpl_ptr< QObject > qobject( new QObject );
const QObject* o = qobject.get();
assertEqual( o, qobject.operator->() );
assertEqual( o, &(qobject.operator*()) );
}
{
kdtools::pimpl_ptr< QObject > o1;
assertTrue( o1 );
kdtools::pimpl_ptr< QObject > o2( 0 );
assertFalse( o2 );
}
{
const kdtools::pimpl_ptr< ConstTester > o1;
kdtools::pimpl_ptr< ConstTester > o2;
assertTrue( o1->isConst() );
assertFalse( o2->isConst() );
assertTrue( (*o1).isConst() );
assertFalse( (*o2).isConst() );
assertTrue( o1.get()->isConst() );
assertFalse( o2.get()->isConst() );
}
}
#endif // KDTOOLSCORE_UNITTESTS
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