How do you test whether a variable is static or not?

[Jonathan M Davis via Digitalmars-d-learn]

I'm writing some serialization code where I need to skip static variables.
So, I have a symbol from a struct, and I'd like to test whether it's static
or not. Ideally, I'd be able to do something like

is(field == static)

but of course that doesn't work. There is __traits(isStaticFunction, ...),
but there is no __traits(isStaticVariable, ...) or __traits(isStatic, ...),
and I don't see anything in std.traits which would help. The closest that
I've been able to come up with is

template isStaticVar(T, alias field)
{
    enum isStaticVar =
        is(typeof({mixin("auto i = T." ~ field.stringof ~ ";");}));
}

For a more general solution, it would of course need to verify that the
field wasn't a function as well, but in my case, that was already checked
prior to instantiating isStaticVar, so I can skip it here. And what I have
mostly works. However, it would fail miserably if the field were a static
member variable that was non-copyable. If it were, then that code would
would declare it to be non-static. Now, non-copyable structs are rare enough
that I can probably get away with letting that bug stand, but I'd prefer to
correctly detect whether a variable is static or not. Does anyone have a
better idea of how to do this?

- Jonathan M Davis