Re: Comma at end of enum lists

Jacek Luczak
2008-03-29T17:25:49Z

Mikael Pettersson pisze:
> Jacek Luczak writes:
> > Hi All,
> >
> > I've found that in many enum lists, there's a comma at the end, e.g.
> > (arch/x86/kernel/early_printk.c):
> >
> > enum {
> > MAGIC1 = 0xBACCD00A,
> > MAGIC2 = 0xCA110000,
> > XOPEN = 5,
> > XWRITE = 4,
> > };
> >
> > Just out of curiosity, is there any particular reason here (no word in
> > CodingStyle about that).
>
> Yes. This idiom allows you to add or remove items without
> changing adjacent lines.

Yep, that's obvious, one line less in diff after every enum change :)

> In a language with strict a comma-as-separator rule you can
> get this benefit by placing the comma before new items rather
> than after existing items:
>
> enum { FOO
> ,FIE
> ,FUM
> };
>
> but luckily C doesn't need this perversion.
>

I was just curious, because it's not common schema (some miss extra comma).

Thanks,
-Jacek