Proper Types

• A type is called proper under any of these circumstances:
  1. It is a native type.
  2. It is a class with constructor, destructor, copy constructor, and assignment operator that manage the type as if it were a native type.
  3. It is a user defined type (class) whose variables are proper types.
• Client programs can use the type exactly as if it were a native type

{
  IntArray a;         // IntArray with default number of elements
  IntArray b(100);    // IntArray with 100 elements
  IntArray c(100,-1); // IntArray with 100 elements each initialized to -1
...
  b = a;
...
  a = b = c;
...
}
// destructor for each object a, b, c is called as they go out of scope
// order of destruction is reverse of order of declaration