Boost C++ Libraries: Ticket #9750: iterator_range to iterator_range & implicit conversion

Steven Watanabe — Thu, 06 Mar 2014 22:09:31 GMT

Replying to psiha:

AFAICT, should be safe WRT strict-aliasing-rules...

It is not. An iterator_range<T> is not an iterator_range<T const> and cannot safely be treated as such just because they happen to have the same layout.

Domagoj Šarić — Fri, 07 Mar 2014 08:09:02 GMT

I was thinking of the 'aggregate or union' bullet/"exception" of the strict aliasing rules, doesn't it come into play in this case?

Domagoj Šarić — Fri, 07 Mar 2014 08:17:02 GMT

Hmm, giving it more thought, I guess it doesn't apply here because iterator_range<T> is not a member of iterator_range<T const> (or vice verse), only their members are 'compatible' but the the aliasing rules/exception don't actually cover that?

i.e. struct A { int * p; }; struct B { int const * p; };

objects of A and B cannot alias each other?

status changed; resolution set

Neil Groves — Sat, 08 Mar 2014 21:01:55 GMT

status new → closed
resolution → invalid

This request doesn't make sense. iterator_range<T const> is totally unrelated to iterator_range<T>.