mirror of
https://git.lyx.org/repos/lyx.git
synced 2024-12-05 06:41:24 +00:00
125 lines
1.8 KiB
C
125 lines
1.8 KiB
C
|
// -*- C++ -*-
|
||
|
/**
|
||
|
* \file cow_ptr.h
|
||
|
* This file is part of LyX, the document processor.
|
||
|
* Licence details can be found in the file COPYING.
|
||
|
*
|
||
|
* \author Angus Leeming
|
||
|
*
|
||
|
* A pointer with copy-on-write semantics
|
||
|
*
|
||
|
* The original version of this class was written by Yonat Sharon
|
||
|
* and is freely available at http://ootips.org/yonat/
|
||
|
*
|
||
|
* I modified it to use boost::shared_ptr internally, rather than use his
|
||
|
* home-grown equivalent.
|
||
|
*/
|
||
|
|
||
|
#ifndef COW_PTR_H
|
||
|
#define COW_PTR_H
|
||
|
|
||
|
#include <boost/shared_ptr.hpp>
|
||
|
|
||
|
|
||
|
namespace lyx {
|
||
|
namespace support {
|
||
|
|
||
|
template <typename T>
|
||
|
class cow_ptr {
|
||
|
public:
|
||
|
explicit cow_ptr(T * = 0);
|
||
|
cow_ptr(cow_ptr const &);
|
||
|
cow_ptr & operator=(cow_ptr const &);
|
||
|
|
||
|
T const & operator*() const;
|
||
|
T const * operator->() const;
|
||
|
T const * get() const;
|
||
|
|
||
|
T & operator*();
|
||
|
T * operator->();
|
||
|
T * get();
|
||
|
|
||
|
private:
|
||
|
boost::shared_ptr<T> ptr_;
|
||
|
void copy();
|
||
|
};
|
||
|
|
||
|
|
||
|
template <typename T>
|
||
|
cow_ptr<T>::cow_ptr(T * p)
|
||
|
: ptr_(p)
|
||
|
{}
|
||
|
|
||
|
|
||
|
template <typename T>
|
||
|
cow_ptr<T>::cow_ptr(cow_ptr const & other)
|
||
|
: ptr_(other.ptr_)
|
||
|
{}
|
||
|
|
||
|
|
||
|
template <typename T>
|
||
|
cow_ptr<T> & cow_ptr<T>::operator=(cow_ptr const & other)
|
||
|
{
|
||
|
if (&other != this)
|
||
|
ptr_ = other.ptr_;
|
||
|
return *this;
|
||
|
}
|
||
|
|
||
|
|
||
|
template <typename T>
|
||
|
T const & cow_ptr<T>::operator*() const
|
||
|
{
|
||
|
return *ptr_;
|
||
|
}
|
||
|
|
||
|
|
||
|
template <typename T>
|
||
|
T const * cow_ptr<T>::operator->() const
|
||
|
{
|
||
|
return ptr_.get();
|
||
|
}
|
||
|
|
||
|
|
||
|
template <typename T>
|
||
|
T const * cow_ptr<T>::get() const
|
||
|
{
|
||
|
return ptr_.get();
|
||
|
}
|
||
|
|
||
|
|
||
|
template <typename T>
|
||
|
T & cow_ptr<T>::operator*()
|
||
|
{
|
||
|
copy();
|
||
|
return *ptr_;
|
||
|
}
|
||
|
|
||
|
|
||
|
template <typename T>
|
||
|
T * cow_ptr<T>::operator->()
|
||
|
{
|
||
|
copy();
|
||
|
return ptr_.get();
|
||
|
}
|
||
|
|
||
|
|
||
|
template <typename T>
|
||
|
T * cow_ptr<T>::get()
|
||
|
{
|
||
|
copy();
|
||
|
return ptr_.get();
|
||
|
}
|
||
|
|
||
|
|
||
|
template <typename T>
|
||
|
void cow_ptr<T>::copy()
|
||
|
{
|
||
|
if (!ptr_.unique())
|
||
|
ptr_ = boost::shared_ptr<T>(new T(*ptr_.get()));
|
||
|
}
|
||
|
|
||
|
} // namespace support
|
||
|
} // namespace lyx
|
||
|
|
||
|
#endif // NOT COW_PTR_H
|