vector in C

vector.c

#include <stdio.h>
#include <stdlib.h>

#define VEC_NEW(type) struct vector { \
    type *start; \
    size_t cap; \
    size_t size; \
} *

#define VEC_RESET(v) \
    v = (typeof(v)) malloc(sizeof(typeof(v))); \
    v->start = (typeof(v->start)) malloc(sizeof(typeof(*v->start))); \
    v->cap = 0; \
    v->size = 0

#define VEC_RESIZE(v, new_cap) \
    v->start = (typeof(v->start)) realloc(v->start, new_cap); \
    v->cap = new_cap; \

#define VEC_PUSH(v, val) \
    if (v->cap == v->size) { VEC_RESIZE(v, (2 * v->cap + 1)) }\
    v->start[v->size++] = val

#define VEC_POP(v) \
    v->start[--v->size]

#define VEC_GET(v, idx) \
    v->start[idx]

#define VEC_SIZE(v) \
    v->size

#define VEC_CLEAR(v) \
    v->size = 0;

int main() {
    VEC_NEW(int) vec;
    VEC_RESET(vec);
    VEC_PUSH(vec, 10);
    printf("%d\n", VEC_POP(vec));
    VEC_PUSH(vec, 12);
    VEC_PUSH(vec, 13);
    VEC_PUSH(vec, 14);
    VEC_PUSH(vec, 15);
    VEC_PUSH(vec, 16);
    printf("%d\n", VEC_POP(vec));

    for (int i = 0; i < 4; i++) {
        printf("%d\n", VEC_GET(vec, i));
    }
}