Memory used for reference counted data might be misaligned.
Memory returned from
g_rc_box_alloc (block_size) might not be suitably aligned
to store some types of objects. The implementation of
gsize private_size = sizeof(GArcBox); char *allocated = g_malloc (private_size + block_size); return allocated + private_size;
allocated will be properly aligned, given current definition of
GArcBox there is no such guarantee about
allocated + private_size.