Re: groff with "nullptr" and (without) gnulib module causes error

[Paul Eggert]

On 2/8/23 14:23, Jeffrey Walton wrote:
> NULL can be a literal 0 (nullptr cannot), so it
> might be Ok to write:
>
>      if (*p != NULL || s.is_empty()) {

Although NULL is allowed to be a literal 0 , that's not required: NULL 
can be nullptr or equivalent. Hence the above code is not portable to 
C++11 or later.

For C++, code should prefer nullptr to NULL (assuming you're using the 
Gnulib nullptr module), to catch porting mistakes like this. The same 
would be true for C except that most GNU code is developed on glibc 
where pre-C23 NULL is ((void *) 0) and so bugs like the above are caught 
at compile-time anyway.