Re: question about nullptr

On Tue, 9 Jul 2024 02:49:49 -0000 (UTC)
Kaz Kylheku <643-408-1753@kylheku.com> wrote:

On 2024-07-08, Michael S <already5chosen@yahoo.com> wrote:

On Sun, 07 Jul 2024 15:17:34 -0700
Keith Thompson <Keith.S.Thompson+u@gmail.com> wrote:
 

 
I just about always use NULL, not 0, when I want a null pointer
constant.  Similarly, I use '\0', not 0, when I want a null
character, 0.0 when I want a floating-point zero, and false when I
want a Boolean zero.  I just like being explicit.
 

>
Pointer: I very rarely use NULL.
Character: I never use '\0'.
Floating point: I never use 0.0. 

 
Never say never!
 
  printf("%f\n", 0);   // undefined behavior.
  printf("%f\n", 0.0); // correct
>

Yes, but that's extremely rare that I want constant (except string
literal) as variable argument to printf().

If you're #define-ing a floating-point constant that has
no fractional part, you should put that .0 there.
>

I am trying hard to avoid #define-ing floating-point constants.
In rare cases where it is not avoidable, most often the constant does
have fractional part. I am not sure what I would prefer when I can't
avoid #define-ing and the constant has no fractional part. Will I write
something like '#define ANSWER ((double)42)' or (42.0) ?
It depends on the mood of the minute.

Someone's going to pass your constant as a variadic argument,
where it doesn't convert to floating-point.
 
Also:
 
  1/3   -> 0
  1/3.0 -> 0.33333...
 
If you're #define-ing a floating point constant that has
no fractional part, and don't include the .0, and the
programmer uses it as a division denominator thinking that
it's a floating-point quantity, oops!