Type Compatibility in Languages

Ada: Name Compatibility

• Derived types are incompatible

  type Temperature is new float;  
  type Salary is new float;  
  
  DailyAve: Temperature := 59.6;
  CeoSalary: Salary;
  
  CeoSalary := DailyAve;  // Illegal
  

• Derived types are incompatible with Parent type

  type Temperature is new float;  
  
  DailyAve: Temperature := 59.6;
  Maxtemp:  float;
  
  MaxTemp := DailyAve;  // Illegal
  

  • Exception: Literal Constants are compatible

    type Temperature is new float;  
    
    DailyAve: Temperature;
    
    DailyAve := 59.6;  // Assigning float constant to derived type - Legal
    

C

• Structure Compatibility for all data types except:
  • struct, which has Name Compatibility

C++