[OT] #define

[Andrew Edwards via Digitalmars-d-learn]

Sorry if this is a stupid question but it eludes me. In the 
following, what is THING? What is SOME_THING?

     #ifndef THING
     #define THING
     #endif

     #ifndef SOME_THING
     #define SOME_THING THING *
     #endif

Is this equivalent to:

     alias thing = void;
     alias someThing = thing*;

Thanks,
Andrew