how to store multi return value provisionally?

[starwing <weasley.wx@...>]

I just read the coroutine section of manual, it says resume function
return a eval result true or false, and the return value of thread.

How can I get the eval result first, but not lost thread return value?

i.e. i want to do that:

??? = coroutine.resume(...)
if ???[1] then
     --- do something with ???[1...]
else
     --- do something with ???[1...]
end

but I don't want to use table, I just wonder it's possible to
implement it just operate the multi-values itself.