On Wed, Mar 29, 2017 at 06:42:37PM -0700, Stefan Beller wrote: > Signed-off-by: Stefan Beller <sbeller@xxxxxxxxxx> No justification? I assume it will be used in a future patch. > diff --git a/column.h b/column.h > index 0a61917fa7..c44a1525a9 100644 > --- a/column.h > +++ b/column.h > @@ -24,6 +24,9 @@ struct column_options { > int padding; > const char *indent; > const char *nl; > + > + /* when non-NULL, use this printing function, fallback to printf */ > + int (*_printf)(const char *__format, ...); > }; Avoid names with leading underscores. They're reserved by the C standard. I wonder if gcc is smart enough to let us mark this function pointer with a "format" attribute so we can get compile-time checking of the format string. -Peff