Ref2 method

P Ref2([
  1. X? o
])

Allocates o into slot '2', or reuses the existing slot '2' allocation if o is null.

Intended as a short-lived scratch reference within a single C call. Use RefUpdate2 if the callee may write back into the pointer.

Implementation

P Ref2([X? o]) => _Ref(o, '2');