pub fn invert<W: Semiring, F: MutableFst<W>>(fst: &mut F)
Invert the transduction corresponding to an FST by exchanging the FST’s input and output labels.
let mut fst : VectorFst<IntegerWeight> = fst![2 => 3]; invert(&mut fst); assert_eq!(fst, fst![3 => 2]);