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Comment by ehmmm | Hacker News Reader

There is no pointer arithmetic in the line:

    struct usb_line6 *line6 = &podhd->line6;

Offset is calculated "below the hood". Pointer arithmetic is defined with arithmetic operands: +,-

-> and . are not arithmetic operands.

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You sound very sure of yourself.

If you look at the definition of the -> and [], you might learn something!

Clearly, you don't have anything constructive to say, so you have to resort to ad hominem.

[] operator doesn't have any place in this debate.

Well, as far as I understand it, `->` works in a similar fashion to `[]`; the difference being that one behaves on arrays while the other on structs.

What @jwatte tried to say is that `->` works like this:

    // foo is struct thingity*
    &foo->bar == foo + offsetof(struct thingity, bar);

The `[]` does a similar thing:

    // s is char*
    *(s+i) == s[i]

Sure, &foo->bar looks like foo + offsetof(struct thingity, bar), but there is no pointer arithmetic involved since C doesn't specify how the member access ( -> or . ) is actually calculated.

It does however specify that [] operator is equivalent to pointer arithmetic. But we are talking ->,. operators and not [].

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