Demo on how to provide a padded wrapper for a struct to ensure it takes up 64Bytes, even as members are added/removed

StructPadding.c

#include <stdio.h>

typedef struct {
    int a;
    int b;
    char c;
} unpadded_t;

typedef struct {
    unpadded_t data;
    char padding[64-sizeof(unpadded_t)];
} padded_t;

int main(int argc, char* argv[]) {
    printf("size of unpadded: %lu\n",sizeof(unpadded_t));
    printf("size of padded: %lu\n",sizeof(padded_t));

    padded_t packet = { .data = { .a=1, .b=2, .c='C' } };
}