Declaring zero size vector

Question

What does the following mean?

struct foo
{
...
char  bar[0];    // Zero size???
};

I asked my colleagues and they told me it\'s the same as

Answer 1

Chris' answer is correct, but I'd probably allocate the object slightly differently.

int n = ...; // number of elements you want
struct foo *p = malloc(offsetof(struct foo, bar[n]));

then iterate over it with

for (int i = 0; i < n; ++i) {
  p->bar[i] = ...;
}

The key point is that Chris' answer works since sizeof(char)==1, but for another type, you'd have to explicitly multiply by sizeof *bar.