[llvm-commits] [PATCH 03/20] [AVX] Remove non-const Iterators

[David A. Greene]

Jakob Stoklund Olesen <stoklund at 2pi.dk> writes:

> On Jul 19, 2011, at 1:11 PM, David Greene wrote:
>
>     -      ListInit *Result = new ListInit(LHSl->begin()+1, LHSl->end(),
>     +      ListInit::const_iterator begin = LHSl->begin()+1;
>     +      ListInit::const_iterator end   = LHSl->end();
>     +      // We can't pass these iterators directly to ArrayRef because
>     +      // they are not convertible to Init **.  Fortunately,
>     +      // RandomAccessIterator::operator * is guaranteed to return an
>     +      // lvalue.
>     +      ListInit *Result = new ListInit(ArrayRef<Init *>(&*begin, end - begin),
>                                           LHSl->getType());
>
> That comment is really scary. ArrayRef requires elements to be laid out continuously in memory. A random access iterator doesn't guarantee that.
> Think std::deque.
>
> How about adding a ListInit method that returns an ArrayRef instead?

Makes sense.  Thanks!

                                  -Dave