> The compiler cannot remove or reorder instructions that have a visible effect. You might be surprised! When it comes to UB compilers can and do reorder/elimi

> The compiler cannot remove or reorder instructions that have a visible effect. You might be surprised! When it comes to UB compilers can and do reorder/eliminate instructions with side effects, resulting in "time travel" [0]. IIRC the upcoming version of the C standard bans this behavior, but the C++ standard still allows it (for now, at least). [0]: https://devblogs.microsoft.com/oldnewthing/20140627-00/?p=633 https://devblogs.microsoft.com/oldnewthing/20140627-00/?p=63...