After a little google search (for instance, site:eel.is "as if rule") I couldn't find a proper place where the so called "as if" rule is clearly stated in the C++ standard. All I could find is that...

In the documentation of std::memory_order on cppreference.com there is an example of relaxed ordering: Relaxed ordering Atomic operations tagged memory_order_relaxed are not synchronization operat...

As the title says: What exactly is the "as-if" rule? A typical answer one would get is: The rule that allows any and all code transformations that do not change the observable behavior...

The "as-if rule" gives the compiler the right to optimize out or reorder expressions that would not make a difference to the output and correctness of a program under certain rules, such as; §1...

Is it possible to have a loop which has a zero execution time? I would think that even an empty loop should have an execution time since there is an overhead associated with it.