mix c and c+++

[Toondalis]

Hi,

newbie question

How can i mix C and C++. and get compile

How could i add memeber function in C

eg

struct animation
{
int bPlay;
Play (int a)
{
// code
}
}

thanks

seewan

[Andreas Kahari]

In article <49**************************@posting.google.com >, Toondalis wrote:

How can i mix C and C++.
This is in the C++ FAQ:

http://www.parashift.com/c++-faq-lit...c-and-cpp.html

How could i add memeber function in C

You can't.
--
Andreas Kähäri

[Ed Morton]

Toondalis wrote:

Hi,

newbie question

How can i mix C and C++. and get compile

How could i add memeber function in C

Best you can do is declare a function pointer within your structure and
then later initialise it to point to the function. Your function should
also take a pointer to the structure so it can access the other data. e.g.

#include "stdio.h"

typedef void (*FP_VOID)(); /* ptr to function returning void */

typedef struct {
int bPlay;
FP_VOID pPlay; /* function pointer */
} ANIMATION;

void Play(ANIMATION *this, int a) {
printf("bPlay=%d\n",this->bPlay);
printf("a=%d\n",a);
}

int main(void) {
ANIMATION anim = { 7, Play };

anim.pPlay(&anim,10);

return 0;
}

Of course, if this is what you need, you may want to reconsider just
using C++. Note that doing the above loses the compilers argument
type-checking ability for "Play".

Regards,

Ed.

[John Bode]

se****@surreal.com.sg (Toondalis) wrote in message news:<49**************************@posting.google. com>...

Hi,

newbie question

How can i mix C and C++. and get compile
Not in the same source file. You can create projects where some files
are written in C and others in C++, but that's kind of out of scope
for this newsgroup.

How could i add memeber function in C

eg

struct animation
{
int bPlay;
Play (int a)
{
// code
}
}

thanks

seewan

C does not allow struct members to be of type "function returning...".
However, you may have struct members that are *pointers* to
functions, e.g.

struct animation
{
int bPlay;
int (*Playfp)(int a);
...
};

int Play (int a)
{
/* code */
}

....
struct animation anm;
anm.Playfp = Play;

anm.Playfp (x);

It's not the same thing as a member function in C++, though; you don't
have a *this pointer, so if you want the function to operate on a
specific instance of struct animation, you'll have to pass a pointer
to that instance, e.g.

struct animation {
int bPlay;
int (*Playfp) (struct animation *anm, int x);
...
};

int Play (struct animation *anm, int x)
{
/* code */
}

struct animation anm1, anm2;

anm1.Playfp = anm2.Playfp = Play;

anm1.Playfp (&anm1, x);
anm2.Playfp (&anm2, x);