Eric Sunshine <sunshine@xxxxxxxxxxxxxx> writes:
> On Fri, May 8, 2020 at 11:18 AM Junio C Hamano <gitster@xxxxxxxxx> wrote:
>> + - Do not explicitly compare an integral value with constant 0 or a
>> + pointer value with constant NULL for equality; just say !value
>> + instead. To validate a counted array at ptr that has cnt elements
>> + in it, write:
>> +
>> + if (!ptr || !cnt)
>> + BUG("array should not be empty at this point");
>> +
>> + and not:
>> +
>> + if (ptr == NULL || cnt == 0);
>> + BUG("array should not be empty at this point");
>
> This talks only about '=='.
Yup. The text would need a matching change, though.
> People might still use 0 or NULL with
> '!='. I wonder if the example can include '!=', as well. Perhaps:
>
> if (!ptr)
> BUG("...");
> if (cnt)
> foo(ptr, cnt);
>
> instead of:
>
> if (ptr == NULL)
> BUG("...");
> if (cnt != 0)
> foo(ptr, cnt);
>
> or something.
Or more succinctly:
if (!ptr || cnt)
BUG("we must have an empty array at this point");
perhaps?
> Also, would you want to talk about not comparing against NUL character?
>
> if (*s)
> foo(s);
>
> instead of:
>
> if (*s != '\0')
> foo(s);
>
> Maybe that's overkill since NUL is an integral value which is already
> covered by your earlier statement (but perhaps some people would
> overlook that).
Yeah, it might be worth saying it explicitly. I dunno.
