* 1.本程序?qū)趖hinking in c++ p409 的“static object destructors ”。
*  2.本程序在與說明全局的static object 和 局部于函數(shù)的 static object的構(gòu)造和析構(gòu)順序
*3.記住書上說：P411。In c++, the constructor for a global static object is called before
* main() is entered, and destroyed as main() exits. 
*4. the constructor of a local static object is called only if the function that includes its definition 
*  is called(如 f1() 中的 對象x1,也就是說如果f1()沒有被調(diào)用則對象x1不會被創(chuàng)建);
*5.p409 like ordinary destructors ,destruction of static objects occurs in the reverse order of initialization.
*/
#include<iostream>
using namespace std;
class X 
{
public:
	X( int ii = 0 ) : m_i( ii ) { cout << "構(gòu)造對象：x" << m_i << endl; }
	
	~X(){ cout << "析構(gòu)對象x" << m_i << endl;  }
private:
	int m_i;           
};

void f()
{
	static  X x1( 1 );     
}

X x2( 2 );   // global ( static storage )!
X x3( 3 );   // global ( static storage )!
int main()
{ 
	cout << "welcome to main() " << endl;
	f();
	cout<< "exiting main()" << endl;
}