How to undef a typedef??

[informativeguy]

Hi,
I did
typedef int Man;

After some code I get a necessity to use the same name Man for char. I
mean to say,I need to
typedef char Man;
But how can I do this???

[Chris Dollin]

in************@ gmail.com wrote:

Hi,
I did
typedef int Man;

After some code I get a necessity to use the same name Man for char. I
mean to say,I need to
typedef char Man;
But how can I do this???

To a good first approximation [1], you can't.

Perhaps you could explain why you've painted yourself into this
corner? We can then discuss the alternatives to paint.

[1] No nested scopes.

--
Chris "hantwig efferko VOOM!" Dollin
"Never ask that question!" Ambassador Kosh, /Babylon 5/

[Eric Sosman]

in************@ gmail.com wrote:

Hi,
I did
typedef int Man;

After some code I get a necessity to use the same name Man for char. I
mean to say,I need to
typedef char Man;
But how can I do this???

Suggestion #1: Don't.

Suggestion #2: Put the two different `Man' uses in different
scopes. For example, use one typedef in function f() and the
other in function g(), and neither at file scope. Or use one at
file scope in source file a.c and the other in source file b.c,
compiled separately.

--
Eric Sosman
esosman@acm

[Tor Rustad]

in************@ gmail.com wrote:

Hi,
I did
typedef int Man;

After some code I get a necessity to use the same name Man for char. I
mean to say,I need to
typedef char Man;
But how can I do this???

You can't use

#undef <identifier>

because the specified <identifierha s to be a macro name, else the
undef will be ignored. However, this works:

#include <stdio.h>
#include <limits.h>

void typedef_func1(v oid)
{
typedef int Man;
Man i;

i = INT_MAX;

printf("INT_MAX : %d\n", i);
}

void typedef_func2(v oid)
{
typedef char Man;
Man c;

c = CHAR_MAX;

printf("CHAR_MA X: %d\n", (int)c);
}

int main(void)
{
typedef_func1() ;
typedef_func2() ;

return 0;
}

--
Tor <torust AT online DOT no>

[Kenneth Brody]

in************@ gmail.com wrote:

>
Hi,
I did
typedef int Man;

After some code I get a necessity to use the same name Man for char. I
mean to say,I need to
typedef char Man;
But how can I do this???

As others have already said, "you can't" and "why would you want to?"

However, you can get close with something like:

typedef whatever Man_t1;
typedef something_else Man_t2;

#define Man Man_t1
...
#undef Man
#define Man Man_t2

--
+-------------------------+--------------------+-----------------------+
| Kenneth J. Brody | www.hvcomputer.com | #include |
| kenbrody/at\spamcop.net | www.fptech.com | <std_disclaimer .h|
+-------------------------+--------------------+-----------------------+
Don't e-mail me at: <mailto:Th***** ********@gmail. com>

[osmium]

"Kenneth Brody" writes:

>Hi,
I did
typedef int Man;

After some code I get a necessity to use the same name Man for char. I
mean to say,I need to
typedef char Man;
But how can I do this???

As others have already said, "you can't" and "why would you want to?"

Perhaps there is more than one programmer involved?

[Flash Gordon]

osmium wrote:

"Kenneth Brody" writes:

Please don't snip the attributions for things you are still quoting.
Kenneth definitely did *not* write the original question. I've
reinstated the attribution for the OPs question.

>>in*********** *@gmail.com wrote:

>>Hi,
I did
typedef int Man;

After some code I get a necessity to use the same name Man for char. I
mean to say,I need to
typedef char Man;
But how can I do this???

As others have already said, "you can't" and "why would you want to?"

Perhaps there is more than one programmer involved?

That would be an excellent reason to NOT do it. As others have
suggested, what the OP is trying to do is a very bad idea.
--
Flash Gordon

[osmium]

"Flash Gordon" <sp**@flash-gordon.me.ukwro te in message
news:h1******** ****@news.flash-gordon.me.uk...

osmium wrote:

>"Kenneth Brody" writes:

Please don't snip the attributions for things you are still quoting.
Kenneth definitely did *not* write the original question. I've reinstated
the attribution for the OPs question.

>in************ @gmail.com wrote:

>>>Hi,
I did
typedef int Man;

After some code I get a necessity to use the same name Man for char. I
mean to say,I need to
typedef char Man;
But how can I do this???
As others have already said, "you can't" and "why would you want to?"

Perhaps there is more than one programmer involved?

That would be an excellent reason to NOT do it. As others have suggested,
what the OP is trying to do is a very bad idea.
--
Flash Gordon

Sorry, I thought must of the people on here could count angle brackets and
figure out who is being responded to.

Hint: One angle bracket is smaller than two angle brackets, therefore the
response was directed at Kenneth Brody. I am not the least bit interested
as to who *he* responded to. I guess I read "why would you want to" as
"why would you need to" or "how did you get in this predicament". I agree
it is a bad idea and tried not to comment on the advisability of doing that.
The OP had already been told several times not to do it and that he can't.
I tried to respond to what I saw as the "new" thing in the thread.

[John Bode]

Eric Sosman wrote:

in************@ gmail.com wrote:

Hi,
I did
typedef int Man;

After some code I get a necessity to use the same name Man for char. I
mean to say,I need to
typedef char Man;

How on Earth did you wind up in that situation?

But how can I do this???

Suggestion #1: Don't.

Suggestion #2: Put the two different `Man' uses in different
scopes. For example, use one typedef in function f() and the
other in function g(), and neither at file scope. Or use one at
file scope in source file a.c and the other in source file b.c,
compiled separately.

Which is still going to be a disaster in its own way. Using the same
name to refer to different types is going to cause problems somewhere
down the line.

It may be time to take a step back and rethink the program's design.

[Random832]

2006-11-16 <4s************ @mid.individual .net>,
osmium wrote:

Hint: One angle bracket is smaller than two angle brackets, therefore the
response was directed at Kenneth Brody. I am not the least bit interested
as to who *he* responded to.

You're still supposed to have exactly as many attribution lines as you
have quote levels. Not more, not less.