#include <iostream>
#include <string>
#include <stdio.h> 
#include <memory>
#include <string.h>
#include <vector>
using namespace std;


class SecSet
{
public:
    typedef shared_ptr<SecSet> Ptr;
private:
    vector<char> _buf;
    // char * _buf=nullptr;
    size_t _len=0;
public:
    SecSet(/* args */){};
    ~SecSet(){
        // if(_buf) delete _buf;
        _len=0;
    }
    void setBuf(const char * buf, size_t len){

        // _buf.clear();
        _buf.assign(buf,buf+len);
        // if(!_buf){
        //     _buf=new char[len] ;_len=len;
        // }
        // if (len>_len)
        // {
        //     _buf=(char*)realloc(_buf,len) ;_len=len;
        // }
        // memcpy(_buf,buf,len);
    }
    void printBuf(){
        printf("%s len %lu\n",_buf.data(),_buf.size());
    }

    Ptr clone(){
        return make_shared<remove_reference<decltype(*this)>::type>(*this); 
    }
};



int main(){
    const char hl[]={"Hello World!"};
    const char hl2[]={"Hello World_twic!"};
    SecSet::Ptr A=make_shared<SecSet>() ;
    A->setBuf(hl,sizeof(hl));
    A->printBuf();
    auto B=A->clone();
    A->setBuf(hl2,sizeof(hl2));
    A->printBuf();
    B->printBuf();
    A->setBuf(hl,sizeof(hl));A->printBuf();
    B->printBuf();
    return 0;
}