Introduction to the Collection Classes
Collection Class Hierarchy
Overall Implementation Structure
Smart Pointers
The following features of Collection Classes pointer types give you the choices shown in the table below. Standard C++ pointers are included for comparison.
| Destruction of Pointed Objects | |||
| Not managed | When out-of-scope | Reference counted | |
| Collections call element operations on pointer | Standard C++ pointer | IAutoPointer | IMngPointer |
| Collections call element operations on referenced object | IElemPointer | IAutoElemPointer | IMngElemPointer |
Smart pointers can only take arguments of type class or struct. This is because the overloaded operator-> needs to return an object of such a type. You can apply pointer objects from these five classes in the same way you use ordinary C++ pointers, with the * and -> operators. Elements are implicitly deleted except in the case of IElemPointer. To delete an element referred to by an IElemPointer you must use an explicit conversion to the referenced element type:
IElemPointer<E> ptr; // ... delete (E*) ptr;
If you want element functions to work on the elements referenced by the pointers, the Collection Classes offer the IElemPointer, IAutoElemPointer and IMngElemPointer pointer classes, which are instantiated with the element type. Pointers of these classes automatically apply all element functions, except for assignment, to the referenced object. Element pointers are constructed from C++ pointers. The C++ dereferencing operators * and -> are defined, for element pointers, to refer to the referenced objects.
The dynamically created elements are not automatically deleted when they are removed from the collection.
Introduction
to the Collection Classes
Collection
Class Hierarchy
Overall
Implementation Structure
Smart
Pointers
Constructing Smart
Pointers
Using Automatic
Pointers
Using Element
Pointers
Using Managed
Pointers
Things to Watch Out
For When Using Smart Pointers
Adding an Element to
a Collection
Removing an Element
from a Collection
Taking Advantage of
the Abstract Class Hierarchy
