i wasn't able to do a dynamic array of function pointers, i have troubles understanding how to work with a dynamic array of function pointers when having a pointer to the func_cmp pointer.
int(*func_cmp[])(void *,void*);
numElements++;
func_cmp=(func_cmp*)realloc(func_cmp, numElements*sizeof(func_cmp*));
func_cmp[numElements-1]=*func_cmp;
i'm not sure about the realloc line.
Clearest way is to use typedef
#include <stdlib.h>
typedef int (*functype)(void *a, void *);
functype funcs[100]; // static array
functype *moreFuncs; // dynamic array
int main() {
int capacity = 16; // initial capacity
int n = 0; // initial size
moreFuncs = malloc(capacity*sizeof(functype)); // heap dynamic array
// ...
// adding element and need more space
if (n >= capacity) {
capacity *= 2;
moreFuncs = realloc(moreFuncs, capacity);
moreFuncs[n++] = <address of new function>;
}
}
malloc to allocate the initial array and resize via realloc as needed.
malloc above + the pointer to that memory as the first argument.capacity = 10, size = 0) and when size >= capacity first double the capacity , realloc using the new capacity, add the new element, and increment the size. Calling realloc each time you add an entry is generally not a sensible way to resource memory.
reallocapproach is that calls tomalloc/calloc/reallocare relatively expensive. So creating an initial bock of pointers sufficient to meet your anticipated needs is generally the best approach. Then call realloc, if and only if you need more. It's a tradeoff. If you are on some embedded system with virtually no spare mem, then your realloc-for-each approach may make sense. Otherwise, allocate a sensible number to begin with an then realloc as-needed.