Boolean datatypes

[Robert L. Fair]

At the risk of being flamed, I've been using enums for a proper boolean
datatype for years:

	typedef enum { false=0,true } bool;

	bool	flag=false;

	if(!flag)
		...
This has _lots_ of advantages over the usual #defines - especially with
a decent compiler which will barf on constructs like:

	flag=10;	 /* correct syntax error,10 is neither true nor false */
or
	enum	states {activate,inactive,comatose} state;
	flag=state;	 /* correct syntax error - a  state isn't a boolean */

Many current C compilers now implement enums properly (i.e. each enumeration
is a distinct type) yet they are hardly ever used. Any comments why not ?

Rob Fair
Bell Communications Research
ihnp4!pyuxv!cim2