Extended STL, Volume 1: Collections and Iterators

Chapter 30. Adapting COM Collections

	Age and treachery will overcome youth and skill.
	--Fausto Coppi

	Stoke me a clipper, I’ll be back for Christmas!
	--Arnold J. Rimmer, Red Dwarf

Introduction

The COM collection model represents collections with a loosely defined interface containing some or all of the following members: the methods Add(), Clear(), and Remove() and the properties Count and Item. (When expressed in C/C++, COM properties are prefixed with get_, e.g., get_Count().) The one mandatory member is _NewEnum, which returns an enumerator in the form of a COM enumerator interface (Section 28.3). Just for grins, _NewEnum may be either a method or a property. By convention COM collections provide enumerators with the IEnumVARIANT interface ...