Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!usc!cs.utexas.edu!yale!cmcl2!rna!kc
From: kc@rna.UUCP (Kaare Christian)
Newsgroups: comp.lang.c++
Subject: const enums -- Lawyers opinions??
Keywords: const, enum
Message-ID: <963@rna.UUCP>
Date: 8 Jan 90 13:56:23 GMT
Organization: Rockefeller University - Neurobiology
Lines: 21

Hey there language lawyer types...

I ran across the following while using Zortech C++ 2. The behavior
seems wrong to me, but I couldn't decide from the ugly reddish
manual what was the correct behavior.

In the following example, my intent is to declare a constant enum by or'ing 
together some enum constants. What I discovered with ZTC is that I can
only do this if I cast each of the enum values to const. Since enum values
are already constants (but not "const", it seems), this seems burdensome.
Is this a Zortechism, or is this standard C++ behavior?

enum bits { zero = 1, one = 2, two = 4 };

bits ZeroAndOne = zero | one;	// OK

const bits OneAndTwo = one | two;	// Fails with ztc2.01
	// complaint is type mistmatch, had <enum bits> and <const enum bits>

const bits OneAndTwoAgain = (const bits)one | (const bits)two;	// OK
	// but casts on the right look very redundant