Hi,
with the fantastic __buildin_object_size of gcc-4.3.* I
managed to implicitly count the number of array elements
passed as function args on the fly -- and this without
loosing type checks. See example below, if interested.
However, I look for a way to achive the same with gcc-3.4-*
if possible. Since the port of gcc-4.3* to windows is far
before being ready. And maybe there is another solution
anyway?
Felix
Example (for gcc-4.3 only!):
/* struct with 2 "func args" to be entred later */
typedef struct{
int i;
double d;
} val;
/* struct to keep the args plus len of array */
typedef struct{
val* pval;
int len; /* gets set by macro */
} array;
/* the demo func to be called
* here twice with the same array type (quite
* useless) */
void f(array a1, array a2){
printf("elements %d, int %d, double %lf\n",
a1.len, /* 1 element */
a1.pval[0].i, /* 1 */
a1.pval[0].d); /* 1 */
printf("elements %d, int %d, double %lf\n",
a2.len, /* 2 elements */
a2.pval[0].i, /* 2 */
a2.pval[0].d); /* 2 */
printf("elements %d, int %d, double %lf\n",
a2.len, /* 2 elements */
a2.pval[1].i, /* 3 */
a2.pval[1].d); /* 3 */
}
/* using __builtin_object_size divided by the
* sizeof(one element) to get the # of elements */
#define macro(...)\
({ val _val[]={__VA_ARGS__};\
array _array={_val,__builtin_object_size(_val,0)/sizeof(val)};\
_array;})
/* calling f and passing arrays of different sizes */
f(macro({1,1}),macro({2,2},{3,3}));
