If the last element of a C struct is an array, sizeof will consider it empty
Got there from: https://redis.io/topics/internals-sds and created this small program that outputs 16:
#include <stdio.h>
struct sdshdr {
long len;
long free;
char buf[];
};
int main() {
struct sdshdr s;
printf("sizeof(s): %lu\n", sizeof(s));
return 0;
}See wikipedia: https://en.wikipedia.org/wiki/Flexible_array_member