/usr/include/wv2/sharedptr.h is in libwv2-dev 0.4.2.dfsg.1-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 | /* This file is part of the KDE libraries
Copyright (c) 1999 Waldo Bastian <bastian@kde.org>
Copyright (c) 2001-2003 Werner Trobin <trobin@kde.org>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License version 2 as published by the Free Software Foundation.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
*/
#ifndef SharedPTR_H
#define SharedPTR_H
#include "dllmagic.h"
namespace wvWare {
/**
* Reference counting for shared objects. If you derive your object
* from this class, then you may use it in conjunction with
* @ref SharedPtr to control the lifetime of your object.
*
* Specifically, all classes that derive from Shared have an internal
* counter keeping track of how many other objects have a reference to
* their object. If used with @ref SharedPtr, then your object will
* not be deleted until all references to the object have been
* released.
*
* You should probably not ever use any of the methods in this class
* directly -- let the @ref SharedPtr take care of that. Just derive
* your class from Shared and forget about it.
*
* @author Waldo Bastian <bastian@kde.org>
*/
class WV2_DLLEXPORT Shared {
public:
/**
* Standard constructor. This will initialize the reference count
* on this object to 0
*/
Shared() : count( 0 ) { }
/**
* Copy constructor. This will @em not actually copy the objects
* but it will initialize the reference count on this object to 0
*/
Shared( const Shared & ) : count( 0 ) { }
/**
* Overloaded assignment operator
*/
Shared &operator=( const Shared & ) { return *this; }
/**
* Increases the reference count by one
*/
void _Shared_ref() const { count++; }
/**
* Releases a reference (decreases the reference count by one). If
* the count goes to 0, this object will delete itself
*/
void _Shared_deref() const { if (!--count) delete this; }
/**
* Return the current number of references held
*
* @return Number of references
*/
int _Shared_count() const { return count; }
protected:
virtual ~Shared() { }
private:
mutable int count;
};
/**
* Can be used to control the lifetime of an object that has derived
* @ref Shared. As long a someone holds a SharedPtr on some Shared
* object it won't become deleted but is deleted once its reference
* count is 0. This struct emulates C++ pointers perfectly. So just
* use it like a simple C++ pointer.
*
* @author Waldo Bastian <bastian@kde.org>
*/
template< class T >
struct SharedPtr
{
public:
SharedPtr()
: ptr(0) { }
SharedPtr( T* t )
: ptr(t) { if ( ptr ) ptr->_Shared_ref(); }
SharedPtr( const SharedPtr& p )
: ptr(p.ptr) { if ( ptr ) ptr->_Shared_ref(); }
~SharedPtr() { if ( ptr ) ptr->_Shared_deref(); }
SharedPtr<T>& operator= ( const SharedPtr<T>& p ) {
if ( ptr == p.ptr ) return *this;
if ( ptr ) ptr->_Shared_deref();
ptr = p.ptr;
if ( ptr ) ptr->_Shared_ref();
return *this;
}
SharedPtr<T>& operator= ( T* p ) {
if ( ptr == p ) return *this;
if ( ptr ) ptr->_Shared_deref();
ptr = p;
if ( ptr ) ptr->_Shared_ref();
return *this;
}
bool operator== ( const SharedPtr<T>& p ) const { return ( ptr == p.ptr ); }
bool operator!= ( const SharedPtr<T>& p ) const { return ( ptr != p.ptr ); }
bool operator== ( const T* p ) const { return ( ptr == p ); }
bool operator!= ( const T* p ) const { return ( ptr != p ); }
bool operator!() const { return ( ptr == 0 ); }
operator T*() const { return ptr; }
T* data() { return ptr; }
const T* data() const { return ptr; }
const T& operator*() const { return *ptr; }
T& operator*() { return *ptr; }
const T* operator->() const { return ptr; }
T* operator->() { return ptr; }
int count() const { return ptr->_Shared_count(); } // for debugging purposes
private:
T* ptr;
};
} // namespace wvWare
#endif
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