Is f(++i, ++i) undefined? <p>I seem to recall that in C++11, they made some changes to the sequencing behaviour and that now i++ and ++i have different sequencing requirements.</p> <p>Is <code>f(++i, ++i)</code> still undefined behaviour? What is the difference between <code>f(i++, i++)</code> and <code>f(++i, ++i)</code>?</p>