Would assigning result from a function to a variable ruin an opportunity for tail optimization?

Question

Whenever I have a function to call at the end of another, I always call it on the same line as the return, like so, return foo(x).

Would assigning the result to a variable botch any possibility of tail optimization? Like this,

function(...)
    ...
    tmp = foo(x)
    return tmp
end

Answer 1

From http://www.lua.org/pil/6.3.html: In Lua, only a call in the format return g(...) is a tail call..

So in this case you are missing the tail call optimization yes.