enum ArgModeAn ownership marker on a for-loop's iterable (ADR 0021): consume xs iterates by moving, mut xs by exclusive borrow.
Cases
case mut_mode
Pass or iterate through an exclusive mutable borrow.
case consume_mode
Transfer ownership to the callee or iterator.
case copy_mode
Copy the value at the call boundary.
case borrow_mode
Pass through a shared borrow.