NULL iterators for <list>

[Howard Hinnant]

On Aug 5, 2013, at 10:47 AM, Marshall Clow <mclow.lists at gmail.com> wrote:

> On Aug 2, 2013, at 11:55 AM, Marshall Clow <mclow.lists at gmail.com> wrote:
>> On Aug 2, 2013, at 11:24 AM, Howard Hinnant <hhinnant at apple.com> wrote:
>> 
>>> On Aug 1, 2013, at 1:05 PM, Marshall Clow <mclow.lists at gmail.com> wrote:
>>> 
>>>> http://std.org/jtc1/sc22/wg21/docs/papers/2013/n3644.pdf  says that value-initialized iterators should compare equal.
>>>> 
>>>> Implement that for std::list.
>>>> 
>>>> There are interactions with libc++'s debug mode; hence the extra tests.
>>> 
>>> Looks pretty good.  Just a couple of comments.
> 
> I think I've addressed your comments, and cleaned up the tests for == and != per our discussion.
> Revised (and simpler) patch enclosed.
> tested under C++03, C++11, C++1Y (each with and w/o debug)

Looks good except:  Please revert src/debug.cpp prior to committing.  We don't want that change.

Howard