From: Garance A Drosehn <drosihn@...>
Date: 2005-08-03T01:14:35+09:00
Subject: enum collection of constant values

I'd like to have a set of constants for a class, where their values
need to be unique, and preferably compact.  For instance:
   SB_NONE = 0; SB_GOOD = 1; SB_BAD = 2; SB_LOGIC_ERR = 3;
   SB_MAX = SB_LOGIC_ERR

but if I want to modify this list by adding something in the middle,
then I have to remember to increment (by hand) all the values
which come after that new value.

In C, I would do something like:
    typedef enum { SB_NONE, SB_GOOD, SB_BAD,
        SB_LOGICERR } sb_set;

Looking through the pickaxe book, it looks like the closest thing
I can do is to create an array of words, and then use the indexes
of where those words are in the array.  But that isn't really the
same thing.   I'd like the efficiency of having constant values,
which would be referred to by name.

(And after I have that for a compact set of values, I'd want a
similar feature which would give me a bit-wise unique set of
values.  Eg:  SB_MODA = 1; SB_MODB = 2; SB_MODC = 4;
SB_MODD = 8; -- such that I could combine the values together
using '|', and tell which values were 'or'-ed together to get that
combined value...)

-- 
Garance Alistair Drosehn     =             drosihn@gmail.com
Senior Systems Programmer               or   gad@FreeBSD.org
Rensselaer Polytechnic Institute;             Troy, NY;  USA