Casts pobject to a pointer to a class_name object.
The name of the class being cast to.
The pointer to be cast to a pointer to a class_name object.
pobject must either be NULL, or point to an object of a class which is derived directly, or indirectly, from class_name. In builds of your application with the _DEBUG preprocessor symbol defined, the macro will ASSERT if pobject is not NULL, or if it points to an object that is not a "kind of" the class specified in the class_name parameter (see CObject::IsKindOf). In non-_DEBUG builds, the macro performs the cast without any type checking.
The class specified in the class_name parameter must be derived from CObject and must use the DECLARE_DYNAMIC and IMPLEMENT_DYNAMIC, the DECLARE_DYNCREATE and IMPLEMENT_DYNCREATE, or the DECLARE_SERIAL and IMPLEMENT_SERIAL macros as explained in the article CObject Class: Deriving a Class from CObject.
For example, you might cast a pointer to CYourDocument, called pYourDoc, to a pointer to CDocument using this expression:
CDocument* pDoc = STATIC_DOWNCAST(CDocument, pYourDoc);
If pYourDoc does not point to an object derived directly or indirectly from CDocument, the macro will ASSERT.