If you retrieve an ENUM value in a numeric context, the column
value's index is returned. For example, you can retrieve numeric
values from an ENUM column like this:
mysql> SELECT enum_col+0 FROM tbl_name;
So the easiest solution is to change your query to
"SELECT StudentID, StudentClub+0 FROM students" (note: the trailing ";"
isn't necessary either).
I doubt there's a mysql++-specific solution for this (although others
know far more than me), because mysql++ isn't given any information
about the mappings between ENUM names and numbers.