Thread: Exporting functions via a struct

Anyone tried this before? would I need to make an API macro at all or is the below example fine?

Code:

typedef struct apihandle apihandle_t;
typedef struct apiname {
  int (*begin)( apihandle_t *handle );
  int (*end)( apihandle_t *handle );
} apiname_t;

int apinameOpen( apiname_t* api );
int apinameOpen( apiname_t* api );

For the why of this it's because this api will wrap around multiple routes to doing the same thing (like there is OpenGL & DirectX) and a struct seems the simplest way t, basically it attempts to acquire one route and if it fails attempts to acquire the next.

Before I forget about it again, someone reported an issue with the code I posted a LONG time ago on this thread: Potentially useful code
but I forgot to take a look at it, well now I have and have fixed the issue, for the sake of forcing the existance of macros like INT_DIG this code can be used/referenced, detecting the bits will need an alternative macro though.

Code:

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

typedef unsigned int ui_t;
typedef long long ll_t;
typedef unsigned long long ull_t;

#define B10_MOD10(BITS) ((BITS) % 10)
#define B10_DIV10(BITS) (((BITS) / 10) * 3)
#define B10_BIT2DIG(BITS) ( B10_DIV10(BITS) + \
    ((B10_MOD10(BITS) == 0) ? (B10_DIV10(BITS) != 0) : \
    ((B10_MOD10(BITS)/3) + ((B10_MOD10(BITS)%3)!=0)) ))

ui_t base10_bit2dig( ui_t bits ) {
    ui_t a = bits % 10;
    ui_t b = (bits / 10) * 3;
    return b + ((a == 0) ? (b != 0) : ((a/3) + ((a%3) != 0)));
}

int main() {
static ui_t const cap = (sizeof(ll_t)*CHAR_BIT);
    ui_t i = 0u, d, e;
    ull_t v = 0u;
    while ( i < cap ) {
        d = base10_bit2dig(i);
        e = B10_BIT2DIG(i);
        printf( "BITS: %02u; DIGS: %02u; EDIG: %02u; VAL: %llu\n", i++, d, e, v );
        v <<= 1;
        v |= 1u;
    }
    return 0;
}

Sure, that's a fairly common way to do object-oriented C.

Thanks, currently doing this without a compiler (long overdue system cleanup in progress) so couldn't check. BTW what process APIs are there? I already know about tlhelp.h, psapi.h & the dirent.h/stdio.h combi for "/proc/" - basically I'm tired of there being no crossplatform API/framework for this process stuff so I thought to make one (GitHub - awsdert/paw: Process API Wrapper) and am trying to use the system API to forfull a simple API that I can use on any system (then I'll try to translate CheatEngine into C)