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Re: [RFC] libstdc++/8780
- From: Joe Buck <jbuck at synopsys dot com>
- To: libstdc++ at gcc dot gnu dot org
- Date: Wed, 4 Dec 2002 10:06:08 -0800 (PST)
- Subject: Re: [RFC] libstdc++/8780
> > The short answer is that, given
> > std::vector<T>::iterator iter_T;
> > then
> > &*iter_T
> > has type T* and points to the same object. As the elements of a vector
> > must be contiguous, this works portably.
> Unfortunately, it will not work for an iterator pointing at the end
> of a container.
You are of course correct that there are no guarantees that
&*some_vector.end() will not produce a one-past-the-end pointer;
debugging implementations of vector<T>::iterator will very likely
throw an exception or abort.
Still, note that I said "has type T* and points to the same object":
in most cases, users that complain about this are trying to interface
data in a vector to a function that wants a pointer, and for them
the &*iter_T mechanism will do.
The most common case where I've needed to use the &* construction is to
pass data in a vector<T> to some function that wants a const T* and
perhaps a count.