literal binary?

Stephen Mayes

Is there any way to represent a literal numerical value in binary?
My wish would be something like 0b0011 instead of the hex 0x0F.
( if this is even the same. )

Sometimes I find it's easier to use my finger's than my brain.

Nov 14 '05 #1

Artie Gold

Stephen Mayes wrote:[color=blue]
> Is there any way to represent a literal numerical value in binary?
> My wish would be something like 0b0011 instead of the hex 0x0F.
> ( if this is even the same. )[/color]

There is not. Hexadecimal or octal are your options.[color=blue]
>
> Sometimes I find it's easier to use my finger's than my brain.
>[/color]
Oh.

HTH,
--ag


--
Artie Gold -- Austin, Texas
http://it-matters.blogspot.com (new post 12/5)
http://www.cafepress.com/goldsays

Nov 14 '05 #2

Dan Henry

"Stephen Mayes" <delete_stephen@themayeshouse.us> wrote:
[color=blue]
>Is there any way to represent a literal numerical value in binary?
>My wish would be something like 0b0011 instead of the hex 0x0F.
>( if this is even the same. )
>
>Sometimes I find it's easier to use my finger's than my brain.[/color]

Tom Torfs donated some macros awhile back. His Usenet post is quoted
below.

================================================== ===================
From: tomto...@village.uunet.be (Tom Torfs)
Newsgroups: comp.lang.c,comp.arch.embedded
Subject: Binary constant macros
Date: 26 Feb 2004 07:36:35 -0800
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NNTP-Posting-Date: Thu, 26 Feb 2004 15:36:35 +0000 (UTC)

Hello All,

I've been missing the lack of support for binary numeric literals in
C. To get around it I wrote the following handy macros, which allows
you to simply write something like:

whatever = B8(10101010);

and will translate as:

whatever = 85;

(compile-time constant)

Code below... hopefully it's useful to some of you as well.

greetings,
Tom

/* Binary constant generator macro
By Tom Torfs - donated to the public domain
*/

/* All macro's evaluate to compile-time constants */

/* *** helper macros *** /

/* turn a numeric literal into a hex constant
(avoids problems with leading zeroes)
8-bit constants max value 0x11111111, always fits in unsigned long
*/
#define HEX__(n) 0x##n##LU

/* 8-bit conversion function */
#define B8__(x) ((x&0x0000000FLU)?1:0) \
+((x&0x000000F0LU)?2:0) \
+((x&0x00000F00LU)?4:0) \
+((x&0x0000F000LU)?8:0) \
+((x&0x000F0000LU)?16:0) \
+((x&0x00F00000LU)?32:0) \
+((x&0x0F000000LU)?64:0) \
+((x&0xF0000000LU)?128:0)

/* *** user macros *** /

/* for upto 8-bit binary constants */
#define B8(d) ((unsigned char)B8__(HEX__(d)))

/* for upto 16-bit binary constants, MSB first */
#define B16(dmsb,dlsb) (((unsigned short)B8(dmsb)<<8) \
+ B8(dlsb))

/* for upto 32-bit binary constants, MSB first */
#define B32(dmsb,db2,db3,dlsb) (((unsigned long)B8(dmsb)<<24) \
+ ((unsigned long)B8(db2)<<16) \
+ ((unsigned long)B8(db3)<<8) \
+ B8(dlsb))

/* Sample usage:
B8(01010101) = 85
B16(10101010,01010101) = 43605
B32(10000000,11111111,10101010,01010101) = 2164238933
*/

greetings,
Tom
================================================== ===================

--
Dan Henry

Nov 14 '05 #3

Jens.Toerring@physik.fu-berlin.de

Stephen Mayes <delete_stephen@themayeshouse.us> wrote:[color=blue]
> Is there any way to represent a literal numerical value in binary?
> My wish would be something like 0b0011 instead of the hex 0x0F.
> ( if this is even the same. )[/color]

Well, 0x0F would be "0b01111" if such a thing would exist;-)
But since, at least in my experience, when you deal with single
bits like that the bits typically have a certain meaning (e.g.
they are standing for a on/off flags etc., put together into
a single value) what about defining meaningful names for them
and then combining them with ORs? Like in e.g.

#define WRONLY ( 1 << 0 )
#define RDWR ( 1 << 1 )
#define CREAT ( 1 << 7 )

Thereby you could use ( CREAT | RDWR ) instead of 0x82 (or, even
harder to read, "0b10000010" as you to wish for) and would have
the additional ad- vantage of making the code easier to under-
stand. The program won't get slowed down by that because the
compiler should be able to replace that by the corresponding
constant.
Regards, Jens
--
\ Jens Thoms Toerring ___ Jens.Toerring@physik.fu-berlin.de
\__________________________ http://www.toerring.de

Nov 14 '05 #4