That uses the result of the function directly, rather than dereferencing it. Just like how the glibc `errno` macro works, except that `errno` is special (in sev

That uses the result of the function directly, rather than dereferencing it. Just like how the glibc `errno` macro works, except that `errno` is special (in several ways) rather than a normal thread-local (which, ironically, would be more efficient).