Re: Compiling GCC with g++: a report

[DJ Delorie <dj at redhat dot com>]

> This doesn't do what I want at all.  The goal is to make the *symbolic
> enumeration constants* inaccessible to most code.

Oh.

enum {
 THE_VAL_QUUX_ENUMS
} TheValQuux;

If not defined, you get one enum, THE_VAL_QUUX_ENUMS.  The "authority"
can define it to a list of enums, so it gets expanded.  Now, if we can
figure out a solution to the "enums are the smallest integral type
they fit in" problem, we'd be all set.  This might work with a suitable
terminator on the real list:

enum {
 THE_VAL_QUUX_ENUMS = 32767;
} TheValQuux;

The private header would have something like:

#define THE_VAL_QUUX_ENUMS \
	TVQ_FOO1, \
	TVQ_FOO2, \
	TVQ_FOO3, \
	TVQ_NUM_ENTRIES, \
	TVQ_INT_MAX

If it's OK to have the enums in a header, provided you can't *use* them...

enum {
#ifdef TVQ_AUTHORITATIVE_ENUMS
 TVQ_FOO1,
 TVQ_FOO2,
 TVQ_FOO3,
 TVQ_NUM_ENTRIES,
#endif
 TVQ_INT_SIZER = 32767;
} TheValQuux;

This won't stop a suitably enthusiastic programmer from getting to
them anyway, but that's always the case.

Or...

#ifndef TVG_ENUM
#define TVG_ENUM(X) DONT_USE_ME_TVG_##x
#endif
enum {
  TVG_ENUM(FOO1),
  TVG_ENUM(FOO2),
  TVG_ENUM(FOO3),
} TheValQuux;

With the "authority" suitably defining TVG_ENUM.

Of course, these are all just hacks to hide the enumerations.