Possible bug in gcc (Please Help)...

Possible bug in gcc (Please Help)...

[Thomas J Amato]

Hi,

I created a small test case which gets the following error (using 3.0.3 on
Solaris 2.7):

gcc -x c++ -c enum_test.h
enum_test.h:2: use of enum `colors' without previous declaration

<<snip enum_test.h>>

enum colors;

void func1(colors var1);


Is this a bug in gcc? I can forward declare a class, struct, or union but
not an enum. If this is a bug has it been fixed in 3.0.4 or 3.1? Any help
would be great.

Thanks,

Tom

Re: Possible bug in gcc (Please Help)...

[John Love-Jensen]

Hi Tom,

You cannot forward declare an enum in C++.

The compiler can use a {signed|unsigned|nonsigned} char, short or int for
it.  But the compiler doesn't know what it is using until it sees the enum's
definition.  If it presumed that an enum was 1 byte, 2 byte, 4 byte,
whatever, you may end up with an unfortunate scenario.

My SAS/C++ compiler allows...

signed short enum Foo { kOne = 1, kTwo, kThree };

(Or was it "enum signed short Foo { ..."?)

...but that's a SAS/C++ idiosyncratic extension to C++.  In that situation,
you could have forward declaration of the enum.

--Eljay