If `atomic

This question here indicates that std::atomic<T> is generally supposed to have the same size as T, and indeed that seems to be the case for gcc, clang, and msvc on x86, x64, and ARM.

In an implementation where std::atomic<T> is always lock free for some type T, is it's memory layout guaranteed to be the same as the memory layout of T? Are there any additional special requirements imposed by std::atomic, such as alignment?