Worker0 Class

// worker0.h -- working classes
#ifndef WORKER0_H_
#define WORKER0_H_
#include <string>
class Worker // an abstract base class
{
private:
    std::string fullname;
    long id;
public:
    Worker() : fullname("no one"), id(0L) {}
    Worker(const std::string & s, long n)
    : fullname(s), id(n) {}
    virtual ~Worker() = 0; // pure virtual destructor
    virtual void Set();
    virtual void Show() const;
};
class Waiter : public Worker
{
private:
    int panache;
public:
    Waiter() : Worker(), panache(0) {}
    Waiter(const std::string & s, long n, int p = 0)
    : Worker(s, n), panache(p) {}
    Waiter(const Worker & wk, int p = 0)
    : Worker(wk), panache(p) {}
    void Set();
    void Show() const;
};
class Singer : public Worker
{
protected:
    enum {other, alto, contralto, soprano,
    bass, baritone, tenor};
    enum {Vtypes = 7};
private:
    static char *pv[Vtypes]; // string equivs of voice types
    int voice;
public:
    Singer() : Worker(), voice(other) {}
    Singer(const std::string & s, long n, int v = other)
    : Worker(s, n), voice(v) {}
    Singer(const Worker & wk, int v = other)
    : Worker(wk), voice(v) {}
    void Set();
    void Show() const;
};
#endif

// worker0.cpp -- working class methods
#include "worker0.h"
#include <iostream>
using std::cout;
using std::cin;
using std::endl;
// Worker methods
// must implement virtual destructor, even if pure
Worker::~Worker() {}
void Worker::Set()
{
    cout << "Enter worker's name: ";
    getline(cin, fullname);
    cout << "Enter worker's ID: ";
    cin >> id;
    while (cin.get() != '\n')
        continue;
}
void Worker::Show() const
{
    cout << "Name: " << fullname << "\n";
    cout << "Employee ID: " << id << "\n";
}
// Waiter methods
void Waiter::Set()
{
    Worker::Set();
    cout << "Enter waiter's panache rating: ";
    cin >> panache;
    while (cin.get() != '\n')
    continue;
}
void Waiter::Show() const
{
    cout << "Category: waiter\n";
    Worker::Show();
    cout << "Panache rating: " << panache << "\n";
}
// Singer methods
char * Singer::pv[] = {"other", "alto", "contralto",
"soprano", "bass", "baritone", "tenor"};
void Singer::Set()
{
    Worker::Set();
    cout << "Enter number for singer's vocal range:\n";
    int i;
    for (i = 0; i < Vtypes; i++)
    {
        cout << i << ": " << pv[i] << " ";
        if ( i % 4 == 3)
            cout << endl;
    }
    if (i % 4 != 0)
        cout << endl;
    while (cin >> voice && (voice < 0 || voice >= Vtypes) )
        cout << "Please enter a value >= 0 and < " << Vtypes << endl;
    while (cin.get() != '\n')
        continue;
}
void Singer::Show() const
{
    cout << "Category: singer\n";
    Worker::Show();
    cout << "Vocal range: " << pv[voice] << endl;
}