/*  Filename: PtrsToStructs.cpp
 *
 *  Author: Br. David Carlson
 *
 *  Date:  Oct 8, 2016         Revised:  Oct 12, 2016
 *
 *  Description:  This program sets up a structure type called EmployeeType and then creates
 *  a type for a pointer to a structure of this type.  Any structure of the given type holds
 *  the ID number, name, and wage rate for one employee.  This program dynamically allocates
 *  space for a new EmployeeType structure, uses the pointer to put data into the 3 fields
 *  of the structure, and then uses a pointer to print the data. Two ways of doing all of
 *  this are illustrated.
 */

#include <iostream>
#include <string>

using namespace std;


struct EmployeeType
{
    string Name;
    int IDNum;
    float WageRate;
};

typedef EmployeeType * EmployeePtrType;


int main(void)
    {
    // First way to use a pointer to dynamically allocate a structure and then use the structure to hold data.
    EmployeePtrType EmployeePtr;

    EmployeePtr = new EmployeeType;
    EmployeePtr->Name = "Sally Keffer";
    EmployeePtr->WageRate = 22.95;
    EmployeePtr->IDNum = 6438;

    cout << "Information on Employee:" << endl << endl;
    cout << "ID number: " << EmployeePtr->IDNum << endl;
    cout << "Name: " << EmployeePtr->Name << endl;
    cout << "Wage rate: " << EmployeePtr->WageRate << endl << endl;

    delete EmployeePtr;   // Don't forget to recover the allocated space when you are done with it.

    // Second way to use a pointer to dynamically allocate a structure and then use the structure to hold data.
    // This way is preferred in that it throws an exception if the new operator fails to allocate the memory space.
    EmployeePtrType p;

    try
        {
        p = new EmployeeType;
        }
    catch (...)
        {
        cerr << "Could not allocate memory for a new EmployeeType structure." << endl << endl;
        exit(1);
        }

    p->Name = "Sam Snead";
    p->WageRate = 20.45;
    p->IDNum = 1207;

    cout << "Information on Employee:" << endl << endl;
    cout << "ID number: " << p->IDNum << endl;
    cout << "Name: " << p->Name << endl;
    cout << "Wage rate: " << p->WageRate << endl << endl;

    delete p;   // Don't forget to recover the allocated space when you are done with it.
    return 0;
    }