Re: Switch to nullptr?

[Rik]

On 04/28/2017 02:34 PM, Daniel J Sebald wrote:
> On 04/28/2017 03:36 PM, Rik wrote:
>> On 04/28/2017 08:42 AM, John W. Eaton wrote:
>>> On 04/27/2017 08:01 PM, Rik wrote:
>>>> jwe,
>>>>
>>>> As long as we're requiring C++11, shall we switch over to nullptr rather
>>>> than 0 or NULL?
>>>>
>>>> As an example,
>>>>
>>>> liboctave/system/oct-time.cc:           char *buf = 0;
>>>
>>> If that's what we should be doing for correct C++ code then it seems like
>>> a good change to me.
>>
>> Yes.  The advantage is that nullptr is a literal constant (like 'true' and
>> 'false') and part of the C++ language so available whenever the compiler
>> supports C++11.  And in terms of programming, it makes the programmer's
>> intent quite clear and can avoid accidental conversions of pointers to
>> ints.
>>
>> I made the change in this cset
>> (http://hg.savannah.gnu.org/hgweb/octave/rev/21baad6b35c4).
>>
>> --Rik
>
> FYI, gvim recognizes "nullptr" and highlights with the constant-color
> scheme when the file has extension .cpp, .c++ and .cc.  If the file
> extension is just .c, there is no special highlight for "nullptr".  So
> it's nice that is already addressed.
>
> Is there a compiler setting that will warn when NULL is used to clear a
> pointer rather than nullptr?

I don't think so.  NULL is just a macro that expands to 0 for C++ and (void
*)(0) for C.  Part of being backwards compatible means that nullptr has to
work seamlessly with both '0' and NULL. 

--Rik