scoped_ptr 與 auto_ptr 與 shared_ptr 差別總結

1.auto_ptr 被複制後，将失去原來所緻資源的所有權；

2.scoped_ptr永遠不能被複制或被指派！scoped_ptr 擁有它所指向的資源的所有權，并永遠不會放棄這個所有權；

3.shared_ptr 是可以共享所有權的智能指針；

#include "stdafx.h"

//#include "windows.h"

#include <memory>

#include <iostream>

using std::tr1::shared_ptr;

class Foo

{

public:

Foo()

{

std::cout<<"new Foo()"<<std::endl;

i = 0;

}

~Foo()

{

std::cout<<"destroy Foo()"<<std::endl;

}

void print()

{

std::cout<<"Foo::print"<<std::endl;

}

int i;

};

void OutSharePtr(shared_ptr<Foo> &P)

{

Foo* p = new Foo();

shared_ptr<Foo> sp1(p);

std::cout<<sp1.use_count()<<"::"<<sp1.get()<<std::endl;

shared_ptr<Foo> sp2(sp1);

p->print();

sp2->print();

std::cout<<sp1.use_count()<<"::"<<sp1.get()<<std::endl;

P = sp2;

std::cout<<sp1.use_count()<<"::"<<sp1.get()<<std::endl;

}

void InSharePtr(shared_ptr<Foo> &p)

{

p->i += 100;

std::cout<<p.use_count()<<"::"<<p.get()<<std::endl;

}

#include <algorithm>

char upCase(char c)

{

return toupper(c);

}

int _tmain(int argc, _TCHAR* argv[])

{

shared_ptr<Foo> sp1(new Foo());

shared_ptr<Foo> sp2(sp1);

shared_ptr<Foo> sp3;

sp1->print();

sp2->print();

std::cout<<sp1.use_count()<<"::"<<sp1.get()<<std::endl;

std::cout<<sp3.use_count()<<"::"<<sp3.get()<<std::endl;

sp3.swap(sp1);

std::cout<<sp1.use_count()<<"::"<<sp1.get()<<std::endl;

std::cout<<sp3.use_count()<<"::"<<sp3.get()<<std::endl;

sp3.reset();

std::cout<<sp1.use_count()<<"::"<<sp1.get()<<std::endl;

sp2.reset();

std::cout<<sp1.use_count()<<"::"<<sp1.get()<<std::endl;

sp1.reset();

std::cout<<sp1.use_count()<<"::"<<sp1.get()<<std::endl;

return 0;

}