如下列代码所示的基类（base）及其派生类（derived），则生成一个派生类的对象时，只调用派生类的构造
函数。
#include <iostream>using namespace std; class base {public: base() { cout << "base constructor" << endl; } ~base() { cout << "base destructor" << endl; }}; class derived : public base { public: derived() { cout << "derived constructor" << endl; } ~derived() { cout << "derived destructor" << endl; }};