Bytes structure in C

bytes.c

// Bytes structure to handle the data pointer and size tuple together
// and using a single heap allocation
//      gcc bytes.c -o bytes
//      ./bytes

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

typedef struct
{
    size_t size;
    uint8_t* data;
} bytes;

bytes* new_bytes(size_t size)
{
    if (size == 0) {
        return NULL;
    }

    bytes* b = (bytes*) malloc(sizeof(bytes) + size);
    if (b == NULL) {
        return NULL;
    }

    b->size = size;
    b->data = (uint8_t*)b + sizeof(bytes);
    return b;
}

int main()
{
    bytes* b = new_bytes(30);
    if (b == NULL) {
        printf("Bytes could not be allocated.\n");
        return -1;
    }

    printf(
        "Bytes (struct of %zu bytes) located at %p, with data of "
        "size at %zu starting at %p\n",
        sizeof(bytes), b, b->size, b->data
    );

    free(b);
    return 0;
}