c++ - Why is typeid behaving differently for references and pointers? -

this question has answer here:

• typeid polymorphic types 1 answer
• typeid polymorphic pointers? 2 answers

basically wondering why typeid not return typeinfo of derived type if given pointer derived type.

example:

if having:

class base {   public:     virtual void foo() {       std::cout << "this base speaking" << std::endl;     } };  class derived : public base {   public:     void foo() override {       std::cout << "this derived speaking" << std::endl;     } }; 

the following:

derived obj; base& ref = obj; base* ptr = &obj; std::cout << typeid(obj).name() << std::endl; std::cout << typeid(ref).name() << std::endl; std::cout << typeid(ptr).name() << std::endl; 

would result in:

7derived 7derived p4base 

while this:

obj.foo(); ref.foo(); ptr->foo(); 

would result in:

this derived speaking derived speaking derived speaking 

my guess base* type in itself, namely pointer base not polymorphic , hence statically determined. reason why call foo results in derived version because of dereferencing (->). if i'm right, still find confusing, since object pointed ptr derived.