The C++ standard is famously complicated about atomics and memory order (for a good reason): https://en.cppreference.com/w/cpp/atomic/memory_order https://en.cp

The C++ standard is famously complicated about atomics and memory order (for a good reason): https://en.cppreference.com/w/cpp/atomic/memory_order https://en.cppreference.com/w/cpp/atomic/memory_order But on x86, many of these things don't matter, if I understand correctly.