🚀 go-pugleaf

In article <9209150106.AA15049@brain.diag.amdahl.com> brm30@diag.amdahl.COM (Brian Moyle) writes:
>Hello,
>
>     I'm fairly new to C++ programming, but I've run into a little
>problem that seems to qualify as a bug.  The following program was 
>taken from The Waite Group's, "C++ Programming," by John Berry,
>copyright 1988 (fourth printing -- 1990).  On page 44, the following
>paragraph provides an explanation of how the 'while' loop is exited:

Brian, I'm about to flame John Berry.  This is not directed at you.

This has got to be the worst C++ book I have ever seen.  Run, not walk,
away from it.  Do your best to forget whatever it said.  Mr. Berry
is clearly not competent to write a C++ text.  Of the 10 or so C++
books I have reviewed, this one is by far the worst.  The fact that
it's now in its fourth printing gives evidence to the old adage: there's
a sucker born every minute.

The program in question is incorrect; you'll get the same symptoms
if you build it with cfront.  He is relying on a stupid hack, assuming
that if he says

	double x, y;
	char op;

that if he then says

	cin >> x >> opr >> y;

and you type "exit", the x character will wind up in "opr".  But that
is not how streams work!  A double cannot begin with "e", therefore
nothing is consumed from cin.  The e remains on the input, and opr
does not change.  The only way to read more stuff from cin is to clear
its error flag.  Perhaps an early streams implementation he used happened
to work this way.  But no competent programmer would ever rely on such
an accidental feature.

Even if this program did happen to work, Mr. Berry should be condemned
for teaching beginners to program this way.  What an ugly, disgusting
kludge.




--
Joe Buck	jbuck@ohm.berkeley.edu