C++静态成员变量退出析构

#include 
#include 
#include 
using namespace std;
 
class A
{
public:
    A(){
        cout << "create" << endl;
    }
    ~A(){
        cout << "delete" << endl;
    }
};
 
class B 
{
public:
    B() {};
    ~B(){};
 
private:
    static std::shared_ptr m_instance;
};
 
std::shared_ptr B::m_instance = std::shared_ptr(new A());
int main()
{
    B b;
    cout << "end" << endl;
    return 0;
}