union.c

#include <stdio.h>

typedef union {
    double d;
    int i;
} union_t;

void dump_union(union_t u) {
    unsigned char *c = (unsigned char *)&u;

    int i;
    for (i = 0; i < sizeof(union_t); i++) {
        printf("%02x ", c[i]);
    }

    printf("\n");
}