Re: bounds checking in array.hpp

From: William Kempf (sirwillard_at_[hidden])
Date: 2000-12-19 09:42:31

--- In boost_at_[hidden], Jesse Jones <jejones_at_a...> wrote:
> It's pretty common for one public method to call another even when 
the
> object doesn't strictly satisfy the invariant. There's usually 
nothing
> wrong with the code, but it's awfully annoying to have to weaken 
your
> contract for these occasionaly cases.

Let me clarify my stance.  It's very common for a method to call 
other methods, be the public or private.  However, if the invariants 
aren't still satisfied at the time of the call there's very tight 
coupling between the two methods with no documentation of which 
invariants need not be satisfied.  This can lead to the same bugs 
that can occur with out DBC to begin with.  So, yes, there are cases 
where this "must" be done, but because of the weakened assertions one 
should avoid as many of these cases as one can.  An invariant system 
must allow for this, but a programmer should avoid it.

Bill Kempf