#include <assert.h>
#include <cstddef>
#include <iostream>
using namespace std;
template <typename T>
class SmartPointer{
public:
SmartPointer(T * ptr = 0) : ptr_(ptr){
if(ptr_ != 0)
cnt_ = new size_t(1);
else
cnt_ = NULL;
}
SmartPointer(const SmartPointer& src){
if(src.ptr_ != NULL){
ptr_ = src.ptr_;
cnt_ = src.cnt_;
*cnt_++;
}
else
{
ptr_ = NULL;
cnt_ = NULL;
}
}
SmartPointer& operator=(const SmartPointer& src){
if(ptr_ != src.ptr_){
releaseCnt();
if(src.ptr_ != NULL){
ptr_ = src.ptr_;
cnt_ = src.cnt_;
*cnt_++;
}
else{
ptr_ = NULL;
cnt_ = NULL;
}
}
return *this;
}
~SmartPointer(){
releaseCnt();
}
T& operator*(){
assert(ptr_ != NULL);
return *ptr_;
}
T* operator->(){
assert(ptr_ != NULL);
return ptr_;
}
size_t getCnt(){
if(cnt_ != NULL)
return *cnt_;
else
return 0;
}
private:
T * ptr_;
size_t * cnt_;
void releaseCnt(){
if(ptr_){
(*cnt_)--;
if(*cnt_ == 0){
delete ptr_;
delete cnt_;
}
}
}
};
int main(){
//test1
cout << "start test1:"<<endl;
SmartPointer<int> s1(new int(1));
SmartPointer<int> s2 = s1;
cout << "s1.cnt: " << s1.getCnt() <<endl;
cout << "s2.cnt: " << s2.getCnt() <<endl;
cout << "end test1:"<<endl;
//test2
cout << "start test2:"<<endl;
SmartPointer<int> s3;
SmartPointer<int> s4(new int(1));
s3 = s4;
cout << "s3.cnt: " << s3.getCnt() <<endl;
cout << "s4.cnt: " << s4.getCnt() <<endl;
cout << "end test2:"<<endl;
return 0;
}
Processed:
0.016, SQL:
9
