object and class name reference

[Gary Wessle]

Hi

can I reference the class name from within the object?

thanks

 

[Salt_Peter]

Hi

can I reference the class name from within the object?

thanks

yes, typeid()...

#include <iostream>
#include <typeinfo>

struct A {
virtual ~A() { }
};

struct B : public A {
};

int main()
{
B b;
A& r_a = b;

std::cout << "type of r_a: " << typeid(r_a).name() << std::endl;
}

Note: If you remove the virtual d~tor, you loose.

 

[Kavya]

yes, typeid()...

#include <iostream>
#include <typeinfo>

struct A {
virtual ~A() { }
};

struct B : public A {
};

int main()
{
B b;
A& r_a = b;

std::cout << "type of r_a: " << typeid(r_a).name() << std::endl;
}

Note: If you remove the virtual d~tor, you loose.

What do you mean by "if you remove virtual destructor you lose"?

 

[Salt_Peter]

What do you mean by "if you remove virtual destructor you lose"?

I'ld kindly suggest trying it.
Without a virtual function in type A above, the class hierarchy would
no longer be polymorphic.
The typeid would identify the referenced object as type A erroneously.

Perhaps the following helps, same outcome:

int main()
{
B b;
A* const p_a = &b; // const pointer

std::cout << "type of r_a: " << typeid(*p_a).name() << std::endl;
}

 

[Kai-Uwe Bux]

yes, typeid()...

#include <iostream>
#include <typeinfo>

struct A {
virtual ~A() { }
};

struct B : public A {
};

int main()
{
B b;
A& r_a = b;

std::cout << "type of r_a: " << typeid(r_a).name() << std::endl;
}

On my machine, this prints:

type of r_a: 1B

Does not look exactly like the classname to me.

The standard would allow

#include <iostream>
#include <typeinfo>
struct Mickey_Mouse {};
int main() {
std::cout << typeid(Mickey_Mouse).name() << std::endl;
}

to print Donald_Duck.

[snip]


Best

Kai-Uwe Bux

 

[Diwa]

Did some research on this.
See inline.

On my machine, this prints:

type of r_a: 1B

Does not look exactly like the classname to me.

If on linux, do "c++filt 1B"
This will give unmangled name i.e. "B"

-- Diwakar

 

[Victor Bazarov]

Did some research on this.
See inline.



If on linux, do "c++filt 1B"
This will give unmangled name i.e. "B"

Platform-specific information is off-topic.

The 'name' member function of 'type_info' class is NOT guaranteed to
return anything meaningful. It's all compiler-specific and off-topic.

V

 

[Diwa]

Platform-specific information is off-topic.

The 'name' member function of 'type_info' class is NOT guaranteed to
return anything meaningful. It's all compiler-specific and off-topic.

Yes, you are right and anyway "c++filt" is a cmd line program
and hence not usable in a C++ program even if its for Linux.