ULONG IUnknown::AddRef(void)
Increments the reference count in this interface instance.
Objects implementations are required to support a certain minimum size for the counter that is internally maintained by AddRef. In short, this counter must be at least 31 bits large. The precise rule is that the counter must be large enough to support 2 [to the 31st minus 1 power] outstanding pointer references to all the interfaces on a given object taken as a whole. Just make it a 32 bit unsigned integer, and you'll be fine.
Argument
Type
Description
return value
ULONG
The resulting value of the reference count. This value is returned solely for diagnostic/testing purposes; it absolutely holds no meaning for release code since in certain situations it is unstable