Introduction to ATL
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The latest version of this topic can be found at Introduction to ATL.
ATL is the Active Template Library, a set of template-based C++ classes with which you can easily create small, fast Component Object Model (COM) objects. It has special support for key COM features including: stock implementations of IUnknown, IClassFactory, IClassFactory2, and IDispatch; dual interfaces; standard COM enumerator interfaces; connection points; tear-off interfaces; and ActiveX controls.
ATL code can be used to create single-threaded objects, apartment-model objects, free-threaded model objects, or both free-threaded and apartment-model objects.
Topics covered in this section include:
How a template library differs from a standard C++ library.
What you can and cannot do with ATL.