Simple type-agnostic dynamic array

Vector struct

typedef struct Vector {
size_t capacity;
size_t length;
void **elements;
void (*destroy)(void *data);
} Vector;

Members:

• capacity: The size of elements in memory
• length: The number of real elements stored in the backing elements array
• elements: The dynamic array of void * that holds the vector’s members
• destroy: Optional deallocation function for data inside a node. Typical usage is NULL for stack allocated data and free() for data created with malloc()

Initialize the vector with a default capacity of 2. User is responsible for freeing elements of the vector with vec_destroy(). Returns a non-zero integer if there is an error

int vec_init(Vector *vec, void (*destroy)(void *data));

Initialize the vector with a user-specified capacity. User is responsible for freeing elements of the vector with vec_destroy(). Returns a non-zero integer if there is an error

int vec_init_with_capacity(Vector *vec, void (*destroy)(void *data), size_t cap);

Resets the Vector back to zero without freeing the Vector object itself. Useful for when the Vector is storing temporary objects in a loop

void vec_clear(Vector *vec);
 
/* Usage */
while (1) {
  int i = 1, int j = 2;
 
  vec_push(vec, &i);
  vec_push(vec, &j);
  assert(vec_len(vec) == 2);
 
  vec_clear(vec);
  assert(vec_len(vec) == 0);
}

Frees the underlying array inside a Vector. If destroy was provided when creating the vector, then it is called against each element in the array before the array is freed. Does not destroy the vector itself, that is left up to the user

void vec_destroy(Vector *vec);
 
/* Usage */
vec_destroy(vec);
free(vec);

Grows the backing array to a provided size. Does not destroy any elements already added or shrink the backing array. Returns a non-zero integer if there is a failure.

void vec_grow_to(Vector *vec, size_t new_cap);
 
/* Usage */
vec_grow_to(vec, 10);

Insert data into the vector at a specified index. Any elements at that array and beyond will be moved up to make room. Returns a non-zero integer if there is an error

int vec_insert(Vector *vec, void *data, size_t index);
 
/* Usage */
 
// vec: 1 2 3 4
int i = 99;
vec_insert(vec, &i, 2);
// vec: 1 2 99 3 4

Insert data at the end of the vector. Returns a non-zero integer if there is an error

int vec_push(Vector *vec, void *data);
 
/* Usage */
 
// vec: 1 2 3
int *i = malloc(sizeof(int));
*i = 4;
vec_push(vec, i);
// vec: 1 2 3 4

Gets the stored data at a specified index. Uses safety checks to make sure index is not out of bounds. Returns NULL if there is an error

void *vec_safe_at(Vector *vec, size_t index);

Removes an element from the array and returns the pointer, then moves elements to shrink the array accordingly. Returns NULL if the index is not valid

void *vec_remove(Vector *vec, size_t index);
 
/* Usage */
// vec: 1 2 3 4
int *t = NULL;
t = (int*)vec_remove(vec, 2);
assert(*t == 3);
// vec: 1 2 4

Shrinks the capacity of the vector down to the current length. Returns a non-zero integer if there is an error

int vec_shrink(Vector *vec);

Finds the largest value in the vector and returns a void pointer to the underlying data. Requires a comparison function to compare the data in the vector. This function must return 1 if a > b, -1 if a < b, or 0 if a == b. See the supplied comparison functions below for reference

const void *vec_min(const Vector *vec, int(*cmp)(const void *a, const void *b));

Finds the smallest value in the vector and returns a void pointer to the underlying data. Requires a comparison function to compare the data in the vector. This function must return 1 if a > b, -1 if a < b, or 0 if a == b. See the supplied comparison functions below for reference

const void *vec_max(const Vector *vec, int(*cmp)(const void *a, const void *b));

Comparison functions to compare data in a vector. These functions must return 1 if a > b, -1 if a < b, or 0 if a == b.

int vec_cmp_int(const void *a, const void *b);
int vec_cmp_char(const void *a, const void *b);

Grabs the element at index i without safety checks for better performance. Use with caution

#define vec_at(v, i) (v)->elements[(i)]

Returns the length of the vector

#define vec_len(v) (v)->length

Returns the capacity of the vector

#define vec_cap(v) (v)->capacity