K&R p 130

[mdh]

Hi All,
Just when I thought things were going to get easy!

Structs.

I **thought** I had copied the examples pretty closely, but am getting
a number of errors.
The code:

>>>>>>

#include <stdio.h>
int main (int argc, const char * argv[]) {

struct point {
int x;
int y;
};
struct point makepoint( int, int); /* error. previous decl of
'makepoint' was here*/

struct point p1 = makepoint(8,9);

printf("%d, %d\n", p1.x, p1.y);
}


struct point makepoint(int x, int y) {
struct point temp;
temp.x = x;
temp.y = y;
return temp;
}

The error I got in the past has meant that something has been defined
twice, but as far as I can tell, ( probably incorrectly) I have
declared a struct called point, then declared a function which accepts
two integer arguments and returns a 'point' structure. Clearly I am
missing something.

In addition, I am getting a number of errors in makepoint function
defintion, which may become obvious once my initial query is cleared.
If not, I will ask then.

Lastly, K&R say , on p 130, of the makepoint function, "notice that
there is no conflict between the argument name and the member with the
same name". I assume that this refers to the lines

temp.x = x;
temp.y = y;

Thanks as usual.

[Ian Collins]

Ben Bacarisse wrote:

Ron Ford <ro*@example.in validwrites:

>I don't know if you know it, but your usenet existence is somewhat
ethereal. I can't read your posts although I have the very good
news.individua l.net.

Noted, but I am not sure what I can do. Every one of my posts (that
I've had reason to look for) has shown up in Google for example
(including all of my posts in this thread) but it is possible that my
server is blocked by some parts of Usenet...

Where is it topical to discuss/investigate this?

As another NIN user, I don't think I've missed one of your posts.

--
Ian Collins.

[vippstar]

On Aug 20, 6:20 am, Ben Bacarisse <ben.use...@bsb .me.ukwrote:

Ron Ford <r...@example.i nvalidwrites:

I don't know if you know it, but your usenet existence is somewhat
ethereal. I can't read your posts although I have the very good
news.individual .net.

Noted, but I am not sure what I can do. Every one of my posts (that
I've had reason to look for) has shown up in Google for example
(including all of my posts in this thread) but it is possible that my
server is blocked by some parts of Usenet...

Where is it topical to discuss/investigate this?

Using google groups, I see your posts frequently. I think that Ron
Ford person is a troll.
Google some of his previous articles in comp.lang.c

[Default User]

Ben Bacarisse wrote:

Ron Ford <ro*@example.in validwrites:

I don't know if you know it, but your usenet existence is somewhat
ethereal. I can't read your posts although I have the very good
news.individual .net.

Noted, but I am not sure what I can do.

I'm also using NIN, and I'm seeing lots of posts from you. I think any
problems Ron is having is due to his setup.


Brian

[Harald van =?UTF-8?b?RMSzaw==?=]

On Thu, 21 Aug 2008 11:24:09 -0600, Ron Ford wrote:

Ben, I still don't see your posts, and this is the only scoring I have
for clc:
[comp.lang.c]
!delete From "Ari"

I don't actually know your newsreader's filter, but unless it's case
sensitive or searches for words instead of characters, you're _telling_ it
to delete Ben Bacarisse's messages.

[David Thompson]

On 19 Aug 2008 07:59:18 GMT, Chris Torek <no****@torek.n etwrote:
<snip: struct tag { body } within function>

In article <73************ *************** *******@i24g200 0prf.googlegrou ps.com>
mdh <md**@comcast.n etwrote:

OK..., this is unique only to structs, unions and enums. And if so,

(Presumably the statement here -- ending with a period -- was
meant as a question.) Yes, it is in fact unique to those three.

is this due to the complicated nature of those objects,

Not exactly. Instead, it is due to the fact that those three
things are the three ways that C allows users to define new
data-types.

The "struct" keyword does one of three things:

- refer to an existing struct type;
- declare a new, incomplete struct type; or
- define a new struct type (or -- really the same thing --
complete an incomplete one).

Yes. #1 existing _and visible_, to be absolutely precise.

The union and enum keywords do the same; the only real difference
is when defining types (because a union defines a bunch of
"overlappin g" members, only one of which you can use at a time,
and an enum defines a bunch of integer constants).

union yes, but standardly you can't forward-declare enum (6.7.2.3p2).
I suspect this is because all struct pointers must 'smell' the same,
and so must all union pointers, but enums smell like integer types,
possibly different ones, so pointers to them are allowed to differ. On
implementations where all enums 'are' int, which are many, or all
(data) pointers look the same, which is more, it can be an extension.

<snip rest; long, and good, as usual>
- formerly david.thompson1 || achar(64) || worldnet.att.ne t