Message from C, C++ discussions

— I've just found out that your code has undefined behaviour. Initialize output to 1;

— Hello

— Ohhh okay. Thank You sir 😃

— Yh

— And does the right to left precedence holds true even for function call?

fun(x++, ++x);

Or is it still UB in C++17?

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— Left and right does apply in regards to the assignment operator [expr.ass].
For function calls in c++ C++17 it's no longer undefined behavior but it's unspecified instead.

From [expr.call] "The initialization of a parameter, including every associated value computation and side effect, is indeterminately sequenced with respect to that of any other parameter."

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— Explanation pls

— Hello house, please I need a strong and comprehensive ebook on c++

— 何ですが？

— Undefined or unspecific behavior

— English only