The fact that it deparses as ($i = ($i++)) does not say anything. It still will not say anything about the order in which the assignment and the increment are done.

Did the authors of Perl re-create all compiler/platform specific postincrement issues that exist in C?

Why should they? All they had to do was follow the specifications. And the specification say that the code we are talking about has undefined behaviour.

MANY things are not defined in the perldocs.

And are hence subject to change without a deprecation cycle. Even the smallist patch might radically change the behaviour, including attempts to erase all the files from your disk. That's the nature of undefined behaviour.

Abigail