C的类型转换(type)变量 缺点不进行严格的类型判断
c++类型转换
1.static_cast 内置类型，具有继承关系的类指针和引用
#include <iostream>
using namespace std;
class Animal{};
class Cat:public Animal{};
int main(){
int a = 97;
a = static_cast<char>(a);
cout << a << endl;
Animal *a1;
a1 = static_cast<Cat*>(a1);
Animal a2;
Animal& a21 = a2;
a21 = static_cast<Cat&>(a2);
return 0;
}
2.dynamic_cast 子类转父类
#include <iostream>
using namespace std;
class Animal{};
class Cat:public Animal{};
int main(){
Cat *c1 = NULL;
Animal *a1 = NULL;
a1 = dynamic_cast<Animal*>(c1);
Cat c2;
Cat& c21 = c2;
Animal a2;
a2 = dynamic_cast<Animal&>(c21);
return 0;
}
3.const_cast 增加/删除类型const
#include <iostream>
using namespace std;
class Animal{};
class Cat:public Animal{};
int main(){
const Cat *c1 = NULL;
Cat *c11 = const_cast<Cat *>(c1);//删除const
c1 = const_cast<const Cat *>(c11);//增加const
return 0;
}
4.reinterpret_cast 强制类型转换
#include <iostream>
using namespace std;
class Animal{};
class Cat{};
typedef int(*FUNC2)();
typedef int(*FUNC1)();
int main(){
Animal *a1 =NULL;
Cat *c1 =NULL;
c1 = reinterpret_cast<Cat*>(a1);
//函数指针转换
FUNC2 f2 =NULL;
FUNC1 f1 =NULL;
f1 = reinterpret_cast<FUNC1>(f2);
return 0;
}
请考虑转换后的后果
