Structure Compatibility

• Increased Flexibility

• Reliability decreases

  typedef float temperature;
  typedef float salary;
  
  temperature daily_average = 59;
  salary ceo_salary;
  
  ceo_salary = daily_average;  // Compatible in C++
  

• Harder to Implement
  • Two Records: Identical structure, Dissimilar field names

    struct time
    {
      int hour;
      int minutes;
      int seconds;
    };
    
    struct date
    {
      int day;
      int month;
      int year;
    };
    
    time now   = {18, 30, 0};
    date today = {1, 1, 2000};
    
    today = now;     // Structure-Compatible, Hard to Implement
    

  • Two Arrays: Identical size, Dissimilar subscript range

    ActualParameter: array [0..99] of Integer;
    
    FormalParameter: array [100..199] of Integer;
    

  • Two Enumerated Types: Same ordinality, Different literals

    enum weekday {Monday, Tuesday, Wednesday, Thursday, Friday};
    enum fruit {Apples, Oranges, Grapes, Peaches, Nectarines};
    
    weekday today;
    fruit dessert;
    
    today   = Grapes;
    dessert = Friday;  // Compatible in C++, Hard to Implement
    

  • Self Referencing Structures

    struct employee
    {
      char *name;
      char social_security_num[10];
      float salary;
      int years_with_company;
    
      employee * next;    // Reference to employee
    };