struct and function pointer in C

[subramanian100in]

Can a structure contain function pointers as members ?
If so, where is it useful ?

[Richard Heathfield]

su**************@yahoo.com, India said:

Can a structure contain function pointers as members ?

Yes.

If so, where is it useful ?

It's useful in cases where you need to associate a function pointer with
other data.

--
Richard Heathfield
"Usenet is a strange place" - dmr 29/7/1999
http://www.cpax.org.uk
email: rjh at the above domain, - www.

[newsGroups]

ya we can do this .like

struct abc
{
int a;
char name[10];
int *(functionptr)(int,int);
}n,m;

<su**************@yahoo.comwrote in message
news:11**********************@h3g2000cwc.googlegro ups.com...

Can a structure contain function pointers as members ?
If so, where is it useful ?

[Nick Keighley]

don't top post
newsGroups wrote:

ya we can do this .like

struct abc
{
int a;
char name[10];
int *(functionptr)(int,int);

int (*functionptr)(int,int);

}n,m;

<su**************@yahoo.comwrote in message
news:11**********************@h3g2000cwc.googlegro ups.com...

Can a structure contain function pointers as members ?
If so, where is it useful ?

[Roland Pibinger]

On 20 Feb 2007 04:04:16 -0800, "subramanian100in@...com, India" wrote:

>Can a structure contain function pointers as members ?
If so, where is it useful ?

The following article may give some ideas. It is not perfect and may
be improved but it shows one way to program polymorphically in C:
http://www.codeproject.com/cpp/PolymorphismC.asp

Best wishes,
Roland Pibinger

[Flash Gordon]

Roland Pibinger wrote, On 22/02/07 20:18:

On 20 Feb 2007 04:04:16 -0800, "subramanian100in@...com, India" wrote:

>Can a structure contain function pointers as members ?
If so, where is it useful ?

The following article may give some ideas. It is not perfect and may
be improved but it shows one way to program polymorphically in C:
http://www.codeproject.com/cpp/PolymorphismC.asp

It certainly needs some work. It uses a macro name which is an
underscore followed by a capital in the header, and such names are
reserved for the implementation. It uses the form
type *ptr = (type *)malloc(sizeof(type));
instead of the simpler and more robust
type *ptr = (type *)malloc(sizeof(type));
Also not specifying in prototypes when functions do not take parameters.

I've not actually downloaded the code to check the rest of it.
--
Flash Gordon

[CBFalconer]

Flash Gordon wrote:

>

.... snip ...

>
It certainly needs some work. It uses a macro name which is an
underscore followed by a capital in the header, and such names
are reserved for the implementation. It uses the form

type *ptr = (type *)malloc(sizeof(type));
instead of the simpler and more robust
type *ptr = (type *)malloc(sizeof(type));

I think you failed to complete the editing :-) I fail to see any
gains in simplicity or robustness. Here's something to cut and
paste:

type *ptr = malloc(sizeof *ptr);

--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net>

[Keith Thompson]

Flash Gordon <sp**@flash-gordon.me.ukwrites:

Roland Pibinger wrote, On 22/02/07 20:18:

>On 20 Feb 2007 04:04:16 -0800, "subramanian100in@...com, India" wrote:

>>Can a structure contain function pointers as members ?
If so, where is it useful ?

The following article may give some ideas. It is not perfect and may
be improved but it shows one way to program polymorphically in C:
http://www.codeproject.com/cpp/PolymorphismC.asp

It certainly needs some work. It uses a macro name which is an
underscore followed by a capital in the header, and such names are
reserved for the implementation. It uses the form
type *ptr = (type *)malloc(sizeof(type));
instead of the simpler and more robust
type *ptr = (type *)malloc(sizeof(type));

Simpler, more robust, and identical.

I presume you meant:

type *ptr = malloc(sizeof *ptr);

--
Keith Thompson (The_Other_Keith) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.