Question

Let’s assume I have this code;

class Ingredients{
    public:
        Ingredients(int size,string name);
        int getsize();
    private:
        string name;
        int size;
};

struct Chain{
    Ingredients* ing;
    Chain* next;  
}

And in my main;

int main()
{
    cout<<typeid(Chain).name()<<endl;
    cout<<typeid(Chain->ing).name()<<endl;
    cout<<typeid(Chain->next).name()<<endl; 

}

my headers are;

#include <iostream>
#include <typeinfo>

using namespace std;

and finally outputs;

P8Chain
P12Ingredients
P8Chain

so my question is, will this types are reliable for using it in a code? If the types are changing (because of the P8 and P12 things I am not sure it would be the same) from computer to comp. this types wouldn’t be reliable. What are your opinions?

Also they are not changing on every run.

Answer 1

They depend on your compiler, so don’t use them inside your code.

The C++ standard says the following concerning typeid (section 5.2.8):

The result of a typeid expression is an lvalue of static type const std::type_info and dynamic type const std::type_info or const name where name is an implementation-defined class derived from std::type_info.

What you can do if you want some sort of RTTI is

if (typeid(myobject) == typeid(Chain)) {
    do_something();
}