Re: Numeric constants as strings

From: Shawn O. Pearce <spearce@spearce.org>
Date: Feb 19, 2007, 09:49 UTC
Message-ID: <20070219094955.GE30030@spearce.org>
In-Reply-To: <7virdy8p25.fsf@assigned-by-dhcp.cox.net>

Junio C Hamano <junkio@cox.net> wrote:

Show 15 quoted lines

> Andy Parkins <andyparkins@gmail.com> writes:
> 
> > I'm working on bringing my hash width literals patch up to
> > date now that 1.5.0 has passed.  It's all been trivial apart
> > from one line:
> >
> > #define HASH_WIDTH_ASCII 40
> > -               printf("%-40s %s%s (%d subtrees)\n",
> > +               printf("%-" HASH_WIDTH_ASCII "s %s%s (%d subtrees)\n",
> >
> > This compiles, but I suspect that it's not going to do what I
> > want it to do.
> 
> Doesn't writing "foo" "bar" (two string literals next to each other)
> tell the compiler to concatenate them?

Yes, but here HASH_WIDTH_ASCII is a number... wtf is the compiler generating for the following?

  printf("%-" 40 "s %s%s (%d subtrees)\n",

I did not even realize that was legal C... Now if the 40 was in quotes (e.g. "40") then the concatenate rule would apply and we would get a nice argument to printf.

-- 
Shawn.