Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!sun-barr!cs.utexas.edu!uunet!opusys!rlkd
From: rlkd@opusys.UUCP (R.L.K.Dattatri)
Newsgroups: comp.lang.c
Subject: enum implementation
Keywords: enum, types, char/int
Message-ID: <396@opusys.UUCP>
Date: 25 Jul 89 20:38:00 GMT
Organization: Opus Systems, Cupertino, CA
Lines: 37



	IMPLEMENTATION OF 'ENUM' in A COMPILER

Recently, while using two different compilers I ran into
a problem with the types if 'enum' constants. One of them treated
the 'enum' constants as 'integer' and the other one stored
them as 'single bytes'. So if I compile parts of a program
with these compilers, the results are bad. This could also
happen if a library is made with one compiler and the source
that uses the library is from a different compiler.

Question: What is the standard (ANSI) type of an 'enum' constant?
	  The ANSI-C standard just says
		'Each enumerated type shall be compatible with an 
		 integer type; the choice of type is implementation 
		 defined'.

	  From K&R
	     	'The identifiers in an enumerator list are declared
		 as constants of type int and may appear wherever
		 constants are required.'

Some compilers determine the type based on the number of constants 
in the 'enum' type. Some compilers provide an option to set the
enum constants to 'int's.

So what is the correct way of implementing 'enum'.

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