On Wednesday, 1 July 2015 at 20:01:08 UTC, dd0s wrote:
int scope_id; // 4
short port; // 8 // <-- this is 4 bytes instead of 2
That's expected because scope_id takes 4 bytes, so port has to be
at 8 so it doesn't overlap the preceding int.
The extra two bytes you see in sizeof are probably at the *end*
of the struct, not between the members.
To get rid of them, out align(2) on the outside too:
align(2)
struct yourthing {
align(2):
members
}
That will trim the size. The align inside the struct packs the
members, but still pads the end (which means an array of these
structs will be aligned on the word boundary). The align on the
outside removes the padding at the end, meaning an an array of
the structs would be packed too.
