A standard smart pointer

SmartPointer.h

//
//  SmartPointer.h
//  MemoryDemo
//
//  Created by HangChen on 5/5/15.
//  Copyright (c) 2015 HangChen. All rights reserved.
//

#ifndef __MemoryDemo__SmartPointer__
#define __MemoryDemo__SmartPointer__

#include <stdio.h>
#import <stdlib.h>

/*
*Usage:
*    SmartPointer<SmartPointerValue> v1 = SmartPointer<SmartPointerValue>(new SmartPointerValue(1));
*    {
*        SmartPointer<SmartPointerValue> v2 = SmartPointer<SmartPointerValue>(new SmartPointerValue(2));
*        v1 = v2;
*    }
*    ///Or you can force it to release
*    v1 = NULL;
*/

template <class T> class SmartPointer {
protected:
    T *ref;
    unsigned *ref_count;
    
public:
    SmartPointer() {
        ref = NULL;
        ref_count = NULL;
    }
    
    SmartPointer(T *ptr) {
        ref = ptr;
        ref_count = new unsigned;
        *ref_count = 1;
    }
    
    SmartPointer(SmartPointer<T> const &sptr) {
        ref = sptr.ref;
        ref_count = sptr.ref_count;
        retain();
    }
    
     SmartPointer<T>& operator=(SmartPointer<T> const &sptr) {
        if (this != &sptr) {
            release();
            
            ref = sptr.ref;
            ref_count = sptr.ref_count;
            retain();
        }
        return *this;
    }
    
    ~SmartPointer() {
        release();
    }
    
    
    void printDescription() {
        unsigned count = 0;
        if (ref_count) {
            count = *ref_count;
        }
        printf("%d\n",count);
    }
    
     T* getValue() {
        return ref;
    }
    
protected:
    void retain(){
        if (ref_count) {
            ++*ref_count;
        }
    }
    
    void release(){
        if (ref_count) {
            --*ref_count;
            if (*ref_count == 0) {
                delete ref;
                delete ref_count;
                ref = NULL;
                ref_count = NULL;
            }
        }
    }
    
};

#endif /* defined(__MemoryDemo__SmartPointer__) */