cvector.h

// https://solarianprogrammer.com/2017/01/08/c99-c11-dynamic-array-mimics-cpp-vector-api-improvements/

#ifndef CVECTOR_H
#define CVECTOR_H
#pragma once
#include<stdlib.h>

#define ARRAY_CREATE(T, arr) \
    T *arr = NULL;\
    do {\
    size_t *raw = malloc(2 * sizeof(size_t));\
    raw[0] = 0;\
    raw[1] = 0;\
    arr = (void *)&raw[2];\
} while (0)

#define ARRAY_DESTROY(arr)\
    do{\
        size_t *raw = ((size_t *)(arr)-2);\
        free(raw);\
        arr = NULL;\
    } while (0)

#define ARRAY_SIZE(ARR)(*((size_t *)ARR - 2))

#define ARRAY_CAPACITY(ARR)(*((size_t *)ARR - 1))

#define ARRAY_PUSH(arr, value)\
    do{\
        size_t *raw = ((size_t *)(arr)-2);\
        raw[0] = raw[0] + 1;\
        if (raw[1] == 0)\
        {\
            raw[1] = 1;\
            raw = realloc(raw, 2 * sizeof(size_t) + raw[1] * sizeof((value)));\
            (arr) = (void *)&raw[2];\
        }\
        if (raw[0] > raw[1])\
        {\
            raw[1] = 2 * raw[1];\
            raw = realloc(raw, 2 * sizeof(size_t) + raw[1] * sizeof((value)));\
            (arr) = (void *)&raw[2];\
        }\
        arr[raw[0] - 1] = (value);\
    } while (0)

#endif