C++ 析构函数 virtual 虚析构

#include<iostream>
#include<memory>

class AAA {
public:
    AAA() { printf("AAA 构造 ... \n"); }
    //virtual ~AAA() { printf("AAA 析构 ... \n"); }
    virtual void SayOk() = 0;
};

class aaa :public AAA {
public:
    aaa() { printf("aaa 构造 ... \n"); }
    ~aaa() { printf("aaa 析构 ... \n"); }
    virtual void SayOk() { printf("aaa SayOk ... \n"); }
};

void test()
{
    //aaa aa;

    if (1)
    {
        std::shared_ptr<AAA> sp = std::make_shared<aaa>();
        sp->SayOk();
        sp = nullptr;
    }

    printf("-------------- 分隔线 -------------- \n");

    if (1)
    {
        AAA * pp = new aaa();
        pp->SayOk();
        delete pp;
        pp = nullptr;
    }

}

int main()
{
    test();
    return 0;
}