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From: drw@cullvax.UUCP
Newsgroups: comp.lang.ada
Subject: Ranges with no values...
Message-ID: <1107@cullvax.UUCP>
Date: Fri, 17-Apr-87 11:06:42 EST
Article-I.D.: cullvax.1107
Posted: Fri Apr 17 11:06:42 1987
Date-Received: Sat, 18-Apr-87 06:20:23 EST
Organization: Cullinet Software, Inc., Westwood, MA
List-Id: <comp.lang.ada>


firth@sei.cmu.edu points out that a generic instantiation can create a
variable whose type is a subrange containing *no* values.  Thus, any
assignment to that variable must raise a CONSTRAINT_ERROR.  This leads
to the interesting fact that one can have

	lower_bound <= variable && variable <= upper_bound

be false!  One would naively expect that this expression would be true
even for uninitialized variables.  What is the official word on
uninitialized variables in Ada?

Dale
-- 
Dale Worley		Cullinet Software
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Un*x (a generic name for a class of OS's) != Unix (AT&T's brand of such)