Basic vectors/arrays in C

main.c

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

struct Vector {
    int size;
    uint8_t* offset;
};

void vector_resize(struct Vector* vec, int newsize) {
    vec->offset = realloc(vec->offset, newsize);
    vec->size = newsize;
}

struct Vector vector_init(uint8_t* init, int init_size) {
    struct Vector vec;
    vec.size = 0;

    if(init != NULL) {
        vector_resize(&vec, init_size);
        memcpy(vec.offset, init, init_size);
    }

    return vec;
}

void vector_set(struct Vector* vec, int idx, uint8_t value) {
    if(idx > vec->size-1) {
        vector_resize(vec, idx+1);
    }
    vec->offset[idx] = value;
}

void vector_append(struct Vector* vec, uint8_t value) {
    vector_set(vec, vec->size, value);
}

int vector_read(struct Vector* vec, int idx) {
    return vec->offset[idx];
}

void vector_destroy(struct Vector* vec) {
    if(vec->size == 0) return;
    free(vec->offset);
    vec->size = 0;
}

int main() {
    uint8_t init[] = {1,2,3};
    struct Vector vec = vector_init(init, 3);
    vector_append(&vec, 30);
    vector_append(&vec, 3);
    printf("Vector size: %d\n", vec.size);

    for(int i=0; i < vec.size; i++) {
        uint8_t val = vector_read(&vec, i);
        printf("Index %d: %d\n", i, val);
    }

    return 0;
}