#include <iostream>using namespace std;#include <stdlib.h>#include <unistd.h>void f(){cout<<"call f()"<<endl;}void func(){	cout << "into func()" << endl;	_exit(0);	cout << "out func()" << endl;}class A{public:	A(){cout<<"A()"<<endl;}	~A(){cout<<"~A()"<<endl;}};int main(){	A obj;	atexit(f);	cout << "hello" << endl;	func();	cout << "world" << endl;}