Bruno Preiss Book base Object implementation problem

[entellus]

Hello all,

Data Structures and Algorithms with Object-Oriented Design Patterns in C++ - author Bruno Preiss

Does anyone know of/have a solutions manual to the book above ?

The particular problem I'm having is in Data Types and Abstraction chapter implementing the Object class.

Thanks in advance.

[RedSon]

Hello all,

Data Structures and Algorithms with Object-Oriented Design Patterns in C++ - author Bruno Preiss

Does anyone know of/have a solutions manual to the book above ?

The particular problem I'm having is in Data Types and Abstraction chapter implementing the Object class.

Thanks in advance.

The book's website should be able to tell you that better then us. If you want help with your homework, there are plenty of nice people who will lend you a hand or give you hints for a tricky part. No one here is going to do your homework for you but everyone needs help now and again. So ask you question if you got it. And, welcome to thescripts.

testlink

[entellus]

thanks for the response. i'll just be more specific.

error: 'HashValue' does not name a type

when compiling the following code:

#include<iostream>
using namespace std;
#include <typeinfo>
 
class Object
{
protected:
    virtual int CompareTo (Object const&) const = 0;
public:
    virtual ~Object ();
    virtual bool IsNull () const;
    virtual int Compare (Object const&) const;
    virtual HashValue Hash () const = 0;
    virtual void Put (ostream&) const = 0;
};
inline bool operator == (Object const& left, Object const& right)
    { return left.Compare (right) == 0; }
 
inline bool operator != (Object const& left, Object const& right)
    { return left.Compare (right) != 0; }
 
inline bool operator <= (Object const& left, Object const& right)
    { return left.Compare (right) <= 0; }
 
inline bool operator <  (Object const& left, Object const& right)
    { return left.Compare (right) <  0; }
 
inline bool operator >= (Object const& left, Object const& right)
    { return left.Compare (right) >= 0; }
 
inline bool operator >  (Object const& left, Object const& right)
    { return left.Compare (right) >  0; }
 
inline ostream& operator << (ostream& s, Object const& object)
    { object.Put (s); return s; }
 
 
Object::~Object ()
    {}
 
bool Object::IsNull () const
    { return false; }
 
int Object::Compare (Object const& object) const
{
    if (typeid (*this) == typeid (object))
        return CompareTo (object);
    else if (typeid (*this).before (typeid (object)))
        return -1;
    else
        return 1;
}
 

section from the book i'm trying to implement:
Objects in Bruno Preiss's book

Also, not that it matters but this isn't for any class.

[RedSon]

thanks for the response. i'll just be more specific.

error: 'HashValue' does not name a type

section from the book i'm trying to implement:
Objects in Bruno Preiss's book

Also, not that it matters but this isn't for any class.

Well its from a text book so it must be for some sort of class. In the code you provided HashValue is a data type. More specifically it is a user defined data type. So that means that in order for you to use HashValue as a data type you must first define HashValue. Or you can find a library that implements HashValue but that implementation may not be exactly what you want in a hash value.

[entellus]

Well its from a text book so it must be for some sort of class. In the code you provided HashValue is a data type. More specifically it is a user defined data type.

Apologies for not doing enough research up front. Turns out that the HashValue is defined as an unsigned int.
Thanks once again for the help.