Thread: Please point out the problems !!!!!!

Dear all,

I have got a difficult question to point out all the problems in the following C++ header code segments. Could any C++ expert please 'enlight' me?

Thanks a lot,
miss muichu

Code:

/**\file	pets.hpp
*	Classes to model members of household: the pet cat(s) and dog(s)
*
*/

// Forward declarations to avoid including <iostream.h>
namespace std
{
    template<class _E> struct char_traits;
    template<class _E, class _Tr> class basic_ostream;
    typedef basic_ostream<char, char_traits<char> > ostream;
}

using namespace std;

class mouse;  // Mice are peats not pets!
class location;
class collar;

/// Pet cat
class cat
{
public:
	void go_to(location& destination);

	/// @return nul if fails
	mouse* stalk();

	/// Where are
	location where() const;

	/// @return true if the cat comes when called
	virtual bool dinner_time();

	/// put collar on
	virtual set_collar(collar* new_collar);

	/// Get the cat's collar
	virtual collar* getCollar() const;

	void purr (ostream& out);

private:
	// Data members ommitted
};

/// Pet cat
class dog : public cat
{
public:
	// inherits go_to() and where() from cat

	/// @return nul if fails
	mouse* stalk();
	cat* chase_cat(cat* the_cat);

	void purr(ostream& out) { throw "dog don't purr"; )
	void bark(ostrea,& out);
	void walkies();

	/// put collar on
	virtual set_collar(collar* new_collar);

	virtual bool dinner_time() { return true; }

private:
	// Data members ommitted
};

One point I can see is that there is no constructor and destructor in both cat and dog classes so that we should add them back. Moreover, the cat destructor should be made virtual as well.

However, I believe that there are more problems in it. Can help?

You should include <iosfwd> to get your forward i/o declarations.

Code:

void dog::bark(ostrea,& out); // typo

Funny, how you derive dog from cat . A base animal class would be more natural imho.