Notes on the ANSI standard

mike at asgb.UUCP mike at asgb.UUCP
Wed Oct 17 23:58:07 AEST 1984


<>

A couple thoughts on the proposed ANSI C standard.  I'm reading from the
September 12, 1984 draft.

(1)
I too must throw in my vote against the 6 character limit for external
names.  It's time that this vestige of the 60's be thrown out.  I
think previous discussions in this newsgroup have covered the subject
adequately.


(2)
Section 4.1.3 states:

   "With one exception, a member of a union object may not be
   inspected unless the value of the object has been assigned
   using that same member."

HOLY <censored>!!  Whatever happened to overlaying values of differing
types?  One of the more handy uses of unions is overlaying bitfields
with an integer so that the bits can be twiddled individually, but the
integer can be used for block operations on all the bits.  I've also
used similar techniques for decoding bit fields of devices like a
Summagraphic Bitpad, or several mouses.

I will grant that this is not good practice for writing portable code.
But to have these practices forbidden or enforced by the compiler is
totally unreasonable, especially for a systems implementation
language!  (In implementation, enforcing this restriction seems
pretty cumbersome.)


Mike Rosenlof
Burroughs Advanced Systems Group
...hplabs!sdcrdcf!bmcg!asgb!mike



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