Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.c++ > #7849 > unrolled thread

undefined reference to vtable

Back to article view | Back to comp.lang.c++

Contents

  undefined reference to vtable eric <cneric12lin0@gmail.com> - 2011-07-15 16:05 -0700
    Re: undefined reference to vtable Ian Collins <ian-news@hotmail.com> - 2011-07-16 11:35 +1200
    Re: undefined reference to vtable Arvind <bharti.arvind@gmail.com> - 2011-07-15 20:49 -0700

#7849 — undefined reference to vtable

Dear Advanced C/g++ programers:

a simple program about Creating an interface with an Abstract Base
Class. from book (C++ cookbook) page 308, 309. Example 8-11. using a
pure interface.
----------------------
// Example 8-11 Using a pure interface
class Person {
public:
virtual void eat() = 0;
virtual void sleep() = 0;
virtual void walk() = 0;
virtual void jump() = 0;
};

class IAirbone {
public:
virtual void fly() = 0;
virtual void up() = 0;
virtual void down() = 0;
};

class Superhero : public Person, // A superhero *is* a person
public IAirbone { // and flies
public:
virtual void eat();
virtual void sleep();
virtual void walk();
virtual void jump();
virtual void fly();
virtual void up();
virtual void down();
virtual ~Superhero();
};

void Superhero::walk() {
// ...
}

void Superhero::fly() {
// ...
}

// Implement all of the pure virtuals in Superhero's Superclasses...

int main() {

Superhero superman;
superman.walk(); // Superman can walk like a person
superman.fly(); // or fly like a bird
}
---------------------------------------------------
my g++ 4.5.2 (on linux2.6.35-25) response by
-------------------------------------
eric@eric-laptop:~/cppcookbook/ch8$ g++ Example8-11.cpp
/tmp/ccT3nO5t.o: In function `main':
Example8-11.cpp:(.text+0x47): undefined reference to
`Superhero::~Superhero()'
/tmp/ccT3nO5t.o: In function `Superhero::Superhero()':
Example8-11.cpp:(.text._ZN9SuperheroC2Ev[_ZN9SuperheroC5Ev]+0x24):
undefined reference to `vtable for Superhero'
Example8-11.cpp:(.text._ZN9SuperheroC2Ev[_ZN9SuperheroC5Ev]+0x2e):
undefined reference to `vtable for Superhero'
collect2: ld returned 1 exit status
--------------------------------------------------
actually that book even did not specially define Superhero::walk(),
that is
I add by myself to escape my compile's error(is that right? or book's
is right?)
you can download the source code of that book's example and test by
yourself
http://examples.oreilly.com/9780596007614/
according to book, thses code are compile good in visual c++ 7.1 on
window xp
thanks your help a lot in advance, Eric

[toc] | [next] | [standalone]

#7854

On 07/16/11 11:05 AM, eric wrote:
> Dear Advanced C/g++ programers:
>
> a simple program about Creating an interface with an Abstract Base
> Class. from book (C++ cookbook) page 308, 309. Example 8-11. using a
> pure interface.
> ----------------------
> // Example 8-11 Using a pure interface
> class Person {
> public:
> virtual void eat() = 0;
> virtual void sleep() = 0;
> virtual void walk() = 0;
> virtual void jump() = 0;
> };
>
> class IAirbone {
> public:
> virtual void fly() = 0;
> virtual void up() = 0;
> virtual void down() = 0;
> };
>
> class Superhero : public Person, // A superhero *is* a person
> public IAirbone { // and flies
> public:
> virtual void eat();
> virtual void sleep();
> virtual void walk();
> virtual void jump();
> virtual void fly();
> virtual void up();
> virtual void down();

None of the above need the "virtual" key word.

> virtual ~Superhero();

Why have you given this a virtual destructor?

<snip>

> --------------------------------------------------
> actually that book even did not specially define Superhero::walk(),
> that is
> I add by myself to escape my compile's error(is that right? or book's
> is right?)

They must be defined.

-- 
Ian Collins

[toc] | [prev] | [next] | [standalone]

#7861

On Jul 16, 4:05 am, eric <cneric12l...@gmail.com> wrote:
> Dear Advanced C/g++ programers:
>
> a simple program about Creating an interface with an Abstract Base
> Class. from book (C++ cookbook) page 308, 309. Example 8-11. using a
> pure interface.
> ----------------------
> // Example 8-11 Using a pure interface
> class Person {
> public:
> virtual void eat() = 0;
> virtual void sleep() = 0;
> virtual void walk() = 0;
> virtual void jump() = 0;
>
> };
>
> class IAirbone {
> public:
> virtual void fly() = 0;
> virtual void up() = 0;
> virtual void down() = 0;
>
> };
>
> class Superhero : public Person, // A superhero *is* a person
> public IAirbone { // and flies
> public:
> virtual void eat();
> virtual void sleep();
> virtual void walk();
> virtual void jump();
> virtual void fly();
> virtual void up();
> virtual void down();
> virtual ~Superhero();
>
> };
>
> void Superhero::walk() {
> // ...
>
> }
>
> void Superhero::fly() {
> // ...
>
> }
>
> // Implement all of the pure virtuals in Superhero's Superclasses...
>
> int main() {
>
> Superhero superman;
> superman.walk(); // Superman can walk like a person
> superman.fly(); // or fly like a bird}
>
> ---------------------------------------------------
> my g++ 4.5.2 (on linux2.6.35-25) response by
> -------------------------------------
> eric@eric-laptop:~/cppcookbook/ch8$ g++ Example8-11.cpp
> /tmp/ccT3nO5t.o: In function `main':
> Example8-11.cpp:(.text+0x47): undefined reference to
> `Superhero::~Superhero()'
> /tmp/ccT3nO5t.o: In function `Superhero::Superhero()':
> Example8-11.cpp:(.text._ZN9SuperheroC2Ev[_ZN9SuperheroC5Ev]+0x24):
> undefined reference to `vtable for Superhero'
> Example8-11.cpp:(.text._ZN9SuperheroC2Ev[_ZN9SuperheroC5Ev]+0x2e):
> undefined reference to `vtable for Superhero'
> collect2: ld returned 1 exit status
> --------------------------------------------------
> actually that book even did not specially define Superhero::walk(),
> that is
> I add by myself to escape my compile's error(is that right? or book's
> is right?)
> you can download the source code of that book's example and test by
> yourselfhttp://examples.oreilly.com/9780596007614/
> according to book, thses code are compile good in visual c++ 7.1 on
> window xp
> thanks your help a lot in advance, Eric

Just look at the error "Example8-11.cpp:(.text+0x47): undefined
reference to
> `Superhero::~Superhero()'".
Fix it. Define the destructor for Superhero because you have declared
this in Superhero class.

[toc] | [prev] | [standalone]

Back to top | Article view | comp.lang.c++

csiph-web