C++ please check if it’s correct or not

Question

The assignment is:

Write a tiny library and submit it in files AboutDog.h and AboutDog.cpp.

This library has the only function: 

void AboutDog(const std::string & dogName, unsigned int description)

The function AboutDog outputs on the screen the following text:

This dog is called *dogName*. It is *list of dog features from description*.

description encodes the dogs properties the following way:

1. set bit 0 means the dog is big
2. set bit 1 means the dog is hairy
3. set bit 2 means the dog is brown
4. set bit 3 means the dog is smart

In the header file, define macros DOG_BIG, DOG_HAIRY, DOG_BROWN, DOG_SMART. I should be able to call the function like this:

AboutDog( "Spike", DOG_BROWN | DOG_SMART | DOG_HAIRY );

The above call should produce the output like this:

This dog is called Spike. It is hairy brown smart.

The order of features doesn't matter. Punctuation doesn't matter too. If description==0 skip the second sentence.

is this solution correct :

AboutDog.cpp:

#include "AboutDog.h"

using namespace std;

void AboutDog(const std::string & dogName, unsigned int description) {

cout<<"This dog is called "<<dogName<<". ";

if(description != 0) {

cout<<"It is";

if(description & DOG_BIG) {

cout<<" big";

}

if(description & DOG_HAIRY) {

cout<<" hairy";

}

if(description & DOG_BROWN) {

cout<<" brown";

}

if(description & DOG_SMART) {

cout<<" smart";

}

cout<<"."<<endl;

}

}

AboutDog.h:

#include <iostream>

enum dog{DOG_BIG, DOG_HAIRY, DOG_BROWN, DOG_SMART};

Answer 1

The enumeration type is not done correctly.

The way it is written the compiler is free to assign any four different integer to the four enumeration values.

Just about all compilers will choose the following values;

next to them in comments I am also showing the binary representation.

enum dog{

DOG_BIG = 0, /* 00000000000000000000000000000000 */

DOG_HAIRY = 1, /* 00000000000000000000000000000001 */

DOG_BROWN = 2, /* 00000000000000000000000000000010 */

DOG_SMART = 3} /* 00000000000000000000000000000011 */

This is not what your teacher wants.

You need to explicitly force the compiler to assign your desired values.

Below is the syntax, which uses Hexadecimal number representation,

and in comments is the binary representation.

enum dog{

DOG_BIG = 0x1, /* 00000000000000000000000000000001 */

DOG_HAIRY = 0x2, /* 00000000000000000000000000000010 */

DOG_BROWN = 0x4, /* 00000000000000000000000000000100 */

DOG_SMART = 0x8}; /* 00000000000000000000000000001000 */

The other issue is that your teacher did not tell you to use an enumeration type,

he asked for macros.

I do not know whether it matters, but programming using macros is more error prone than enumeration types. So I like your choice.

But in case this is an exercise about macros, not enumeration types, the syntax is

#define DOG_BIG (0x1)

and so on for the other three values.