addition: Added basic header and structure

include/arraylist.h

@@ -0,0 +1,61 @@
+#ifndef ARRAYLIST_H
+#define ARRAYLIST_H
+
+#include <inttypes.h>
+#include <stddef.h>
+#include <stdbool.h>
+
+typedef struct {
+    void *data;
+    size_t capacity;
+    size_t len;
+    size_t elem_size;
+} ArrayList;
+
+typedef struct {
+    ArrayList array;
+    size_t offset;
+} ArrayListSlice;
+
+typedef enum {
+    ARRLIST_OK = 0,
+    ARRLIST_OUT_OF_BOUNDS,
+    ARRLIST_BAD_ALLOC,
+    ARRLIST_EMPTY,
+    ARRLIST_NULL_ARG,
+    ARRLIST_INVALID_CAPACITY,
+    ARRLIST_INVALID_ELEM_SIZE,
+} ArrayListErr;
+
+typedef struct {
+    bool is_valid;
+    union {
+        ArrayListErr err;
+        ArrayList array;
+    };
+} ArrayListResult;
+
+ArrayListResult arraylist_init(size_t capacity, size_t elem_size);
+ArrayListErr arraylist_destroy(ArrayList *arr);
+ArrayListErr arraylist_clear(ArrayList *arr);
+
+size_t arraylist_size(ArrayList *arr);
+size_t arraylist_capacity(ArrayList *arr);
+bool arraylist_is_empty(ArrayList *arr);
+
+ArrayListErr arraylist_push_back(ArrayList *arr, void *data);
+ArrayListErr arraylist_insert(ArrayList*arr, size_t index, void *data);
+ArrayListErr arraylist_push_front(ArrayList* arr, void *data);
+
+// Here out can be null for not having anything writen
+ArrayListErr arraylist_pop_back(ArrayList *arr, void *out);
+ArrayListErr arraylist_remove_at(ArrayList *arr, size_t index, void *out);
+ArrayListErr arraylist_pop_front(ArrayList *arr, void *out);
+
+ArrayListErr arraylist_get(ArrayList *arr, size_t index, void *out);
+ArrayListErr arraylist_set(ArrayList *arr, size_t index, void *data);
+
+ArrayListErr arraylist_resize(ArrayList *arr, size_t new_capacity);
+ArrayListErr arraylist_reserve(ArrayList *arr, size_t size_to_reserve);
+
+#endif