99 lines
3.2 KiB
C++
99 lines
3.2 KiB
C++
/********************************************************
|
||
* ██████╗ ██████╗████████╗██╗
|
||
* ██╔════╝ ██╔════╝╚══██╔══╝██║
|
||
* ██║ ███╗██║ ██║ ██║
|
||
* ██║ ██║██║ ██║ ██║
|
||
* ╚██████╔╝╚██████╗ ██║ ███████╗
|
||
* ╚═════╝ ╚═════╝ ╚═╝ ╚══════╝
|
||
* Geophysical Computational Tools & Library (GCTL)
|
||
*
|
||
* Copyright (c) 2023 Yi Zhang (yizhang-geo@zju.edu.cn)
|
||
*
|
||
* GCTL is distributed under a dual licensing scheme. You can redistribute
|
||
* it and/or modify it under the terms of the GNU Lesser General Public
|
||
* License as published by the Free Software Foundation, either version 2
|
||
* of the License, or (at your option) any later version. You should have
|
||
* received a copy of the GNU Lesser General Public License along with this
|
||
* program. If not, see <http://www.gnu.org/licenses/>.
|
||
*
|
||
* If the terms and conditions of the LGPL v.2. would prevent you from using
|
||
* the GCTL, please consider the option to obtain a commercial license for a
|
||
* fee. These licenses are offered by the GCTL's original author. As a rule,
|
||
* licenses are provided "as-is", unlimited in time for a one time fee. Please
|
||
* send corresponding requests to: yizhang-geo@zju.edu.cn. Please do not forget
|
||
* to include some description of your company and the realm of its activities.
|
||
* Also add information on how to contact you by electronic and paper mail.
|
||
******************************************************/
|
||
|
||
#ifndef _GCTL_SPTR_H
|
||
#define _GCTL_SPTR_H
|
||
|
||
namespace gctl
|
||
{
|
||
//模板类作为友元时要先有声明
|
||
template <typename T> class smart_ptr;
|
||
|
||
//辅助类
|
||
template <typename T>
|
||
class ref_ptr
|
||
{
|
||
private:
|
||
//该类成员访问权限全部为private，因为不想让用户直接使用该类
|
||
//定义智能指针类为友元，因为智能指针类需要直接操纵辅助类
|
||
friend class smart_ptr<T>;
|
||
ref_ptr() : p(nullptr) {}
|
||
//构造函数的参数为基础对象的指针
|
||
ref_ptr(T *ptr) : p(ptr), count(1) {}
|
||
//析构函数
|
||
~ref_ptr() {delete p;}
|
||
//引用计数
|
||
int count;
|
||
//基础对象指针
|
||
T *p;
|
||
};
|
||
|
||
//智能指针类
|
||
template <typename T>
|
||
class smart_ptr
|
||
{
|
||
public:
|
||
smart_ptr() : rp(new ref_ptr<T>()) {}
|
||
smart_ptr(T *ptr) : rp(new ref_ptr<T>(ptr)) {} //构造函数
|
||
smart_ptr(const smart_ptr<T> &sp) : rp(sp.rp) {++rp->count;} //复制构造函数
|
||
smart_ptr &operator=(const smart_ptr<T>& rhs) //重载赋值操作符
|
||
{
|
||
++rhs.rp->count; //首先将右操作数引用计数加1，
|
||
if (--rp->count == 0) //然后将引用计数减1，可以应对自赋值
|
||
delete rp;
|
||
rp = rhs.rp;
|
||
return *this;
|
||
}
|
||
|
||
T &operator *() //重载*操作符
|
||
{
|
||
return *(rp->p);
|
||
}
|
||
|
||
T *operator ->() //重载->操作符
|
||
{
|
||
return rp->p;
|
||
}
|
||
|
||
~smart_ptr() //析构函数
|
||
{
|
||
if (--rp->count == 0) //当引用计数减为0时，删除辅助类对象指针，从而删除基础对象
|
||
{
|
||
delete rp;
|
||
}
|
||
}
|
||
|
||
T *get()
|
||
{
|
||
return rp->p;
|
||
}
|
||
private:
|
||
ref_ptr<T> *rp; //辅助类对象指针
|
||
};
|
||
}
|
||
|
||
#endif //_GCTL_SPTR_H
|