But what is the code generated when the value of N is not known at compile time. i.e it is a user provided value (which is the more interesting case since it ha

But what is the code generated when the value of N is not known at compile time. i.e it is a user provided value (which is the more interesting case since it happens all the time) -- does the fold still get abstracted into a for-loop kind of thing in the generated code?