I’ve encountered the following couple of snippets of code in a source hive (ok, it’s Nethack) <br
that are causing me trouble regarding Bitfields and what appears to be some reflection going on. <br

Specific error is that BITFIELD is not recognized in XCODE, error comes up on the Bitfield definitions in the Struct. Is there a different way that would be largely compatible available that I'm not finding?

I used to be a professional C++ programmer a decade ago and this isn't how I'd do things at all.

//Definition - It appears that BITFIELDS is defined by default. This code snippets are verified from the nethack source globals.h
    #ifdef BITFIELDS /* Force overriding Bitfields */
    #define Bitfield(x, n) unsigned x : n
    #else
    #define Bitfield(x, n) uchar x
    #endif

//Usage Snippet: from objclass.h
    struct objclass {
    short oc_descr_idx;             /* description when name unknown */
    char *oc_uname;                 /* called by user */
    oc_name_known Bitfield(oc_name_known, 1);     /* discovered */
    Bitfield(oc_merge, 1);          /* merge otherwise equal objects */ /*Reflection?*/
    Bitfield(oc_uses_known, 1);     /* obj->known affects full description;
                                       otherwise, obj->dknown and obj->bknown
                                       tell all, and obj->known should always
                                       be set for proper merging behavior. */
    };

I tried to compile the Nethack source