#define SILC_ID_GET_ID ...

    Returns the ID type specific pointer from the SilcID structure.  As
    the SilcID is able to house all types of IDs this macro can be used
    to get the specific ID from the structure by its type.

    #define SILC_ID_GET_ID(id)                                              \
      ((id).type == SILC_ID_CLIENT  ? (void *)&(id).u.client_id :           \
       (id).type == SILC_ID_SERVER  ? (void *)&(id).u.server_id :           \
       (void *)&(id).u.channel_id)