🚀 go-pugleaf

martin@kcbbs.gen.nz (Martin D Kealey) writes:

[example implementation which can crash if a pointer is referenced
after the memory it points to has been deleted]

>Is there anything in such an implementation that is unconforming?
>If not, then I submit that "undefined behaviour" IS the correct
>term to apply to *any* use of an invalidated pointer value.

I don't think there is any disagreement about whether it IS undefined
behaviour; the question is about whether it should be.  Remember, every
instance in which the standard leaves the behaviour undefined is one
more hurdle for programmers trying to write portable programs.  I think
the possible efficiency gains from allowing optimizations such as the
one you described are likely to be very minimal even on those very rare
systems on which they might apply.  If that were the only reason, I
would think that it ought not be undefined behaviour.

However, the argument that the behaviour should be undefined in order
to support implementations which perform pointer validity checking in
hardware is more convincing.

--
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WWW: <http://www.cs.mu.oz.au/~fjh>   |  of excellence is a lethal habit"
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