C++ Constructor for converting from long to Date, buildin type to your own type

 
#include <iostream>
#include <iomanip>
using namespace std;
class Date {//from   w  w w  .  jav  a  2  s  .  c  om
   private:
   int month, day, year;
   public:
   Date(int = 7, int = 4, int = 2012);  // constructor
   // constructor for converting from long to Date
   Date(long);
   void showDate();
};
// implementation section
Date::Date(int mm, int dd, int yyyy)  // constructor
{
   month = mm;
   day = dd;
   year = yyyy;
}
// constructor for converting from long to Date
Date::Date(long findate)
{
   year = int(findate/10000.0);
   month = int((findate - year * 10000.0)/100.0);
   day = int(findate - year * 10000.0 - month * 100.0);
}
// member function to display a date
void Date::showDate()
{
   cout << setfill('0') << setw(2) << month << '/' << setw(2) << day << '/' << setw(2) << year % 100;
   return;
}
int main()
{
   Date a;   // initialized by the default constructor
   Date b(20141225L);  // initialize with a long integer
   Date c(4,1,2012);   // initialize with the specified values
   cout << "Dates a, b, and c are ";
   a.showDate();
   cout << ", ";
   b.showDate();
   cout << ", and ";
   c.showDate();
   cout << ".\n";
   a = Date(20150103L);  // convert a long to a Date
   cout << "Date a is now ";
   a.showDate();
   cout << ".\n";
   return 0;
}