pub const SENTINEL: i32 = -1;Expand description
Sentinel value used in AssignmentSolution::assign to denote an
unmatched row.
Encoded as a negative i32 so it can never collide with a valid
0-indexed column. The internal CostFiniteDomain for each row
always carries this value as a real domain entry priced at the
caller-supplied AssignmentBuilder::unmatch_penalty; the
branch-and-bound search treats it as just another option whose
dominance is decided by total cost.