多态与非多态向上转型的差异
#include <iostream>
#include <typeinfo>
struct Base1 {
// polymorphic type: declares a virtual member
virtual ~Base1() {}
};
struct Derived1 : Base1 {
// polymorphic type: inherits a virtual member
};
struct Base2 {
// non-polymorphic type
};
struct Derived2 : Base2 {
// non-polymorphic type
};
int main()
{
Derived1 obj1; // object1 created with type Derived1
Derived2 obj2; // object2 created with type Derived2
Base1& b1 = obj1; // b1 refers to the object obj1
Base2& b2 = obj2; // b2 refers to the object obj2
std::cout << "Expression type of b1: " << typeid(decltype(b1)).name() << '\n'
<< "Expression type of b2: " << typeid(decltype(b2)).name() << '\n'
<< "Object type of b1: " << typeid(b1).name() << '\n'
<< "Object type of b2: " << typeid(b2).name() << '\n'
<< "Size of b1: " << sizeof b1 << '\n'
<< "Size of b2: " << sizeof b2 << '\n';
}
