The classes are named using their generic name in this help file.
The "IPC" prefix is omitted (so if you see Queue class name, it is IPCQueue in source code).
The classes in Pascal usually have T* prefix, so IPCQueue in Delphi/C++Builder/FreePascal code will become TIPCQueue.
For declarations that don't have classes (DLL and SO declarations) the name of the class is the first part of the function name. Function declarations are defined so that they accept first parameter, which is in fact a pointer to the class instance.