I would like to use code below for general purpose dynamic array implementation in my future code. Does that look fine?

array.h:

Usage:

First, initialize the array with data type and initial array capacity measured in number of elements that the array can hold:

struct task {
        char *task_name;
        int task_id;
};

struct array my_tasks;
/* Define an dynamic array of struct tasks */
array_init(&my_tasks, 2, sizeof(struct task));

After that, functions in array.h can be used to add, remove, traverse array etc.

I would like to use code below for general purpose dynamic array implementation in my future code. How does it look?

array.h:

How the code is used:

First you initialize the array with a data type and the initial array capacity, measured in the number of elements that the array can hold.

After that, the functions in array.h can be used to add, remove, traverse the array, and more.

Example:

struct task {
    char *task_name;
    int task_id;
};

struct array my_tasks;
/* Define an dynamic array of struct tasks */
array_init(&my_tasks, 2, sizeof(struct task));

I would like to use below code for general purpose dynamic array implementation in my future codes. Does that look fine?

#include <stdlib.h>

/* This file describes structures and functions
   for general purpose dynamic array.
*/

struct array {
    void *data;       /* Points to where the data is */
    int numElements;  /* Number of elements */
    int sizeElem;     /* Size of a single elements */
    int capacity;     /* Current total space in number of elements */
};

/* macros for accessing array internals */
#define array_index(ARRAY, INDEX) (void *)((unsigned)((ARRAY)->data)+(INDEX*((ARRAY)->sizeElem)))
#define array_len(ARRAY) (ARRAY)->numElements
#define array_cap(ARRAY) (ARRAY)->capacity

static inline void array_init(struct array *arr, int capacity, int sizeElem) {
    arr->data = malloc(capacity * sizeElem);
    arr->capacity = capacity;
    arr->sizeElem = sizeElem;
    arr->numElements = 0;
}

/* Add an element to array. Expand array if necessary. */
static inline void array_add(struct array *arr, void *data) {
    if (arr->capacity <= arr->numElements) {
        int new_capacity = 2 * arr->capacity;
        arr->data = realloc(arr->data, new_capacity * arr->sizeElem);
        arr->capacity = new_capacity;
    }
    memcpy(array_index(arr,arr->numElements), data, arr->sizeElem);
    arr->numElements++;
}

/* Macro for traversing array elements. */
#define array_for_each(TYPE, ELEM, ARRAY) \
    for (TYPE *ELEM=(ARRAY)->data; (ELEM - (TYPE *)(ARRAY)->data) < (ARRAY)->numElements; ELEM++)


/* Removes the element at given index and moves other elements if necessary. */
static inline void array_delete_index(struct array *arr, int index) {
    int movables = arr->numElements - index - 1;
    memcpy(array_index(arr, index),
           (void *)((unsigned)array_index(arr, index) + arr->sizeElem),
           movables * arr->sizeElem);
    arr->numElements--;
}

/* If array capacity is too much compared to number of elements,
   reduce array capacity
*/
static inline void array_free_capacity(struct array *arr) {
    if (arr->capacity > 2*arr->numElements) {
        int new_capacity = arr->capacity / 2;
        arr->data = realloc(arr->data, new_capacity * arr->sizeElem);
        arr->capacity = new_capacity;
    }
}

/* Probably useless macro */
#define array_free(ARRAY) free((ARRAY)->data)

/* Search for an element and return an index if found. Otherwise, return -1
   Comparison function should return 0 if two items should be considered equal.
*/
static inline int array_search(struct array *arr, void *target, int (*cmp)(void *first, void *second)) {
    for(int i=0; i<arr->numElements; i++) {
        if(cmp(array_index(arr, i), target) == 0) return i;
    }
    return -1;
}

/* Returns a pointer to the element at given index, if it doesn't exist, return NULL */ static inline void *array_get_index(struct array *arr, int index) { if (index > (arr->numElements - 1)) return NULL; return array_index(arr, index); }

I would like to use code below for general purpose dynamic array implementation in my future code. Does that look fine?

#include <stdlib.h>

/* This file describes structures and functions
   for general purpose dynamic array.
*/

struct array {
    void *data;       /* Points to where the data is */
    int numElements;  /* Number of elements */
    int sizeElem;     /* Size of a single elements */
    int capacity;     /* Current total space in number of elements */
};

/* macros for accessing array internals */
#define array_index(ARRAY, INDEX) (void *)((unsigned)((ARRAY)->data)+(INDEX*((ARRAY)->sizeElem)))
#define array_len(ARRAY) (ARRAY)->numElements
#define array_cap(ARRAY) (ARRAY)->capacity

static inline void array_init(struct array *arr, int capacity, int sizeElem) {
    arr->data = malloc(capacity * sizeElem);
    arr->capacity = capacity;
    arr->sizeElem = sizeElem;
    arr->numElements = 0;
}

/* Add an element to array. Expand array if necessary. */
static inline void array_add(struct array *arr, void *data) {
    if (arr->capacity <= arr->numElements) {
        int new_capacity = 2 * arr->capacity;
        arr->data = realloc(arr->data, new_capacity * arr->sizeElem);
        arr->capacity = new_capacity;
    }
    memcpy(array_index(arr,arr->numElements), data, arr->sizeElem);
    arr->numElements++;
}

/* Macro for traversing array elements. */
#define array_for_each(TYPE, ELEM, ARRAY) \
    for (TYPE *ELEM=(ARRAY)->data; (ELEM - (TYPE *)(ARRAY)->data) < (ARRAY)->numElements; ELEM++)


/* Removes the element at given index and moves other elements if necessary. */
static inline void array_delete_index(struct array *arr, int index) {
    int movables = arr->numElements - index - 1;
    memcpy(array_index(arr, index),
           (void *)((unsigned)array_index(arr, index) + arr->sizeElem),
           movables * arr->sizeElem);
    arr->numElements--;
}

/* If array capacity is too much compared to number of elements,
   reduce array capacity
*/
static inline void array_free_capacity(struct array *arr) {
    if (arr->capacity > 2*arr->numElements) {
        int new_capacity = arr->capacity / 2;
        arr->data = realloc(arr->data, new_capacity * arr->sizeElem);
        arr->capacity = new_capacity;
    }
}

/* Probably useless macro */
#define array_free(ARRAY) free((ARRAY)->data)

/* Search for an element and return an index if found. Otherwise, return -1
   Comparison function should return 0 if two items should be considered equal.
*/
static inline int array_search(struct array *arr, void *target, int (*cmp)(void *first, void *second)) {
    for(int i=0; i<arr->numElements; i++) {
        if(cmp(array_index(arr, i), target) == 0) return i;
    }
    return -1;
}

/* Returns a pointer to the element at given index, if it doesn't
    exist, return NULL
*/
static inline void *array_get_index(struct array *arr, int index) {
    if (index > (arr->numElements - 1)) return NULL;
    return array_index(arr, index);
}