struct and function pointer in C

[subramanian100in]

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

 

[Richard Heathfield]

(e-mail address removed), 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.

 

[newsGroups]

ya we can do this .like

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

 

[Nick Keighley]

don't top post

ya we can do this .like

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

int (*functionptr)(int,int);

 

[Roland Pibinger]

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:

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.

 

[CBFalconer]

.... 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);

 

[Keith Thompson]

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

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);