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#include <iostream>
using namespace std;
class People
{
public:
People()
{
cout << "People constructed" << endl;
}
virtual void speak() = 0;
};
class Man:public People
{
public:
void speak()
{
cout << "A man speaks" << endl;
}
void fight()
{
cout << "A man fights" << endl;
}
};
class Woman:public People
{
private:
Man son;
public:
void speak()
{
cout << "A woman speaks" << endl;
}
void cook()
{
cout << "A woman cooks" << endl;
}
Man getSon()
{
cout << "A woman's son:" << endl;
return son;
}
};
///////////////////////////SubMain//////////////////////////////////
int main(int argc, char *argv[])
{
People *p = new Man();
p->speak();
Man *m = dynamic_cast<Man *>(p);
m->fight();
Man *m2 = (Man *)p;
m2->fight();
try
{
Woman *w = dynamic_cast<Woman *>(p);
// if (w != NULL)
// {
// w->cook();
// w->getSon().speak();
// }
// 如果不检查直接用的话,居然也可以
w->cook();
w->getSon().speak();
}
catch(bad_cast &e)
{
cout << "bad_cast exception" << endl;
}
delete p;
system("pause");
return 0;
}
///////////////////////////End Sub//////////////////////////////////
/************************************************************************/
/* output:
People constructed
A man speaks
A man fights
A man fights
A woman cooks
A woman's son:
A man speaks
*/
/************************************************************************/
class Woman:public People
{
private:
Man son;
int v;
public:
void speak()
{
cout << "A woman speaks" << endl;
}
void cook()
{
cout << "A woman cooks" << endl;
v=0;
}
Man getSon()
{
cout << "A woman's son:" << endl;
return son;
}
};
这么写执行cook的时候就报错了。
指针类型的dynamic_cast转失败了不会抛出异常,dynamic_cast转引用类型失败才会抛出异常。