From: Jason Hise (chaos_at_[hidden])
Date: 2005-07-28 18:59:47
Martin Wille wrote:
>Jason Hise wrote:
>
>>I plan to sneak an improved version of the null developed by Scott
>>Meyers in with this code in a header called boost/null.hpp, and use it
>>in the singleton's implementation. It will be defined as follows:
>>
>>
>[...]
>
>>undef NULL
>>#define NULL (::boost::null)
>>
>>
>I violently object to sneaking in something that fundamental.
>
>
If I was really trying to 'sneak' it in I wouldn't have mentioned it
explicitly on the list. ;)
>I also object to this idea in general. It doesn't buy us much, it breaks
>existing code, it may cause ODR violations, and it also violates the C++
>Standard.
>
What existing code will it break? I would imagine it would only break
code that deserves to be broken in the first place (like int i = NULL).
Also, how would this cause ODR violations? I was under the impression
that the one definition rule required all definitions in different
translation units to be identical, not that it required that a
definition only be provided in one translation unit. And even if
somehow more than one instance of null ended up being used, how would
this actually end up causing a problem? Would your problem with this
code vanish if I removed the NULL definition on the last two lines?
Would it reappear if I moved the null class into the global namespace
(essentially making lowercase null a keyword)?
Please don't take my response as confrontational, I do appreciate the
feedback.
-Jason