Array of bitfields

[Mehta Shailendrakumar]

Hi,

I would like to know why array of bitfields is not possible.
Is there any relation with processor architecture for this?
Thank you for your time.

Regards,
Shailendra

[Tim Rentsch]

"Mehta Shailendrakumar " <sh************ *******@de.bosc h.com> writes:

I would like to know why array of bitfields is not possible.
Is there any relation with processor architecture for this?
Thank you for your time.

Bitfields aren't addressable; you can't take the address of a
bitfield with the '&' operator, for example.

Because bitfields aren't addressable, they can't be used for
arrays, because of how arrays and pointers work. No addresses,
no arrays.

An array of bitfield values may be manufactured using a struct,
thusly:

struct { unsigned value:4; } bitfield_array[10];

i = bitfield_array[0].value;
bitfield_array[1].value = j;

Of course, the values in the array won't be tightly packed.
There will be unused space between the values, unless the number
of bits and the padding requirements for the struct that the
values are in happen by lucky coincidence to leave no wasted
space. But if what you want is an array of bitfield values
and some inter-field padding doesn't matter, this approach
could fill the bill.

[pete]

ya*******@gmail .com wrote:

I agree with you.But,if you have programmed in the Keil 8051 C
compiler, you have a datatype called "bit", which can store a value of
0 or 1.It is used to store certain bit-addressable pin values and is
very commonplace in 8051 C.
for Ex,
bit PIN1 = 0;

That looks like C to you?
If that's 8051 C, then 8051 C, isn't C.

--
pete

[SM Ryan]

pete <pf*****@mindsp ring.com> wrote:
# ya*******@gmail .com wrote:
# >
# > I agree with you.But,if you have programmed in the Keil 8051 C
# > compiler, you have a datatype called "bit", which can store a value of
# > 0 or 1.It is used to store certain bit-addressable pin values and is
# > very commonplace in 8051 C.
# > for Ex,
# > bit PIN1 = 0;
#
# That looks like C to you?
# If that's 8051 C, then 8051 C, isn't C.

ANSI doesn't have a trademark on the third letter of the alphabet.
There are many varieties of C other than ANSI's.

--
SM Ryan http://www.rawbw.com/~wyrmwif/
God's a skeeball fanatic.

[Jean-Claude Arbaut]

Le 18/06/2005 15:53, dans 11************* @corp.supernews .com, «*SM Ryan*»
<wy*****@tang o-sierra-oscar-foxtrot-tango.fake.org> a écrit*:

pete <pf*****@mindsp ring.com> wrote:
# ya*******@gmail .com wrote:
# >
# > I agree with you.But,if you have programmed in the Keil 8051 C
# > compiler, you have a datatype called "bit", which can store a value of
# > 0 or 1.It is used to store certain bit-addressable pin values and is
# > very commonplace in 8051 C.
# > for Ex,
# > bit PIN1 = 0;
#
# That looks like C to you?
# If that's 8051 C, then 8051 C, isn't C.

ANSI doesn't have a trademark on the third letter of the alphabet.
There are many varieties of C other than ANSI's.

Standards are written to avoid spreading of incompatible compilers
(and probably many other good reasons).
You can invent a BASIC-like language and call that C if this pleases you,
but don't come on c.l.c, cause this IS related to ISO C.
If you really don't understand what a standard benefit is, just have a look
at Fortran history before standardization . Look also at BASIC, not
standardized as far as I know, and a least I don't know any two compilers
for the same BASIC variant.

[SM Ryan]

# but don't come on c.l.c, cause this IS related to ISO C.

If you wanted a moderated newsgroup, then make a moderated newsgroup.
Until then, you don't get to decide what other people post.

# If you really don't understand what a standard benefit is, just have a look

Irrelevant. Neither ANSI nor ISO owns a trademark on 'C'.

--
SM Ryan http://www.rawbw.com/~wyrmwif/
So....that would make Bethany part black?

[Jean-Claude Arbaut]

Le 18/06/2005 17:03, dans 11************* @corp.supernews .com, «*SM Ryan*»
<wy*****@tang o-sierra-oscar-foxtrot-tango.fake.org> a écrit*:

# but don't come on c.l.c, cause this IS related to ISO C.

If you wanted a moderated newsgroup, then make a moderated newsgroup.
Until then, you don't get to decide what other people post.

That's right, but it doesn't prevent from flaming. I was several times for
the same reason. Now I know what c.l.c is for, I am careful.

If you wanted a non-ISO C newsgroup, then make a comp.lang.c.bla bla.
Until then, you don't get to decide what is valid here. BTW I considered
this option, but c.l.c and comp.programmin g are sufficient for my usage.

[Martin Ambuhl]

SM Ryan wrote:

# but don't come on c.l.c, cause this IS related to ISO C.

If you wanted a moderated newsgroup, then make a moderated newsgroup.
Until then, you don't get to decide what other people post.

# If you really don't understand what a standard benefit is, just have a look

Irrelevant. Neither ANSI nor ISO owns a trademark on 'C'.

Your post before this merely showed ignorance; this one exposes you as a
troll.
*PLONK*

[CBFalconer]

Martin Ambuhl wrote:

SM Ryan wrote:

# but don't come on c.l.c, cause this IS related to ISO C.

If you wanted a moderated newsgroup, then make a moderated newsgroup.
Until then, you don't get to decide what other people post.

# If you really don't understand what a standard benefit is, just

Irrelevant. Neither ANSI nor ISO owns a trademark on 'C'.

Your post before this merely showed ignorance; this one exposes
you as a troll.
*PLONK*

He has been long gone from here, primarily for inability to mark
quotes correctly. Another indication of a non-intelligent troll.

--
"If you want to post a followup via groups.google.c om, don't use
the broken "Reply" link at the bottom of the article. Click on
"show options" at the top of the article, then click on the
"Reply" at the bottom of the article headers." - Keith Thompson

[Walter Roberson]

In article <42************ ***@yahoo.com>,
CBFalconer <cb********@wor ldnet.att.net> wrote:

He has been long gone from here, primarily for inability to mark
quotes correctly.

There is no "correct" way to mark quotes: only -conventions-
that are followed to various degrees. If you feel that there
is a "correct" way to mark Usenet quotes, then you are welcome to
cite an RFC, IEEE standard, ISO standard, page in K&R (any
edition), any book by K., R., or P., government regulation
in any country, or statute in -any- jurisdiction which has
the authority to create criminal offenses.

And No, the behaviour of your newsreader or of Google Groups
in automatic colorization or other forms of highlighting
are -not- evidence of "correct" behaviour.
Keith got it right months ago: there is no "correct" way of
marking quotes, just ways that irritate different sets of people.

-Every- quoting convention offends -someone-; it is up to each
individual to choose which set of people they are willing to offend.

--
"I want to make sure [a user] can't get through ... an online
experience without hitting a Microsoft ad"
-- Steve Ballmer [Microsoft Chief Executive]

[Martijn]

>> He has been long gone from here, primarily for inability to mark

quotes correctly.
There is no "correct" way to mark quotes: only -conventions-
that are followed to various degrees.

[snipped]
-Every- quoting convention offends -someone-; it is up to each
individual to choose which set of people they are willing to offend.

Just like "incorrect" separators for the signatures. Then again, these
conventions are there to make the life of a poster more convenient, and I
comply only for that reason. And honestly, a _lot_ of software depends on
those conventions, not only for color highlighting, but also for readjusting
message width and the sorts.

"Can't we all just get along??" :P

--
Martijn
http://www.sereneconcepts.nl