I seen quora question https://www.quora.com/What-are-the-best-features-introduced-in-C++17 about C++17 best features, where I read printf("%d %d", i++, i++)
no longer undefined behavior in C++17.
Last to second paragraph of answer written by Sergey Zubkov:
Oh, and it’s no longer undefined behavior to do printf("%d %d", i++, i++), although it’s still undefined behavior to do i++ + i++.
So, I have a question in my mind, is it really defined behaviour in C++17?