Struct ExactlyOne 

pub struct ExactlyOne { /* private fields */ }

Global constraint enforcing that exactly one variable in scope takes target_value.

Implementations

impl ExactlyOne

pub fn new( variables: impl IntoIterator<Item = VariableId>, target_value: i64, ) -> Self

Creates an ExactlyOne constraint over variables for target_value.

Complexity

Time & Space: O(N) where N is number of variables.

Trait Implementations

impl Clone for ExactlyOne

fn clone(&self) -> ExactlyOne

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Constraint for ExactlyOne

fn name(&self) -> &str

Returns a human-readable name of the constraint type.

fn scope(&self) -> &[VariableId]

Returns the slice of variable IDs involved in this constraint.

fn is_satisfied(&self, assignment: &HashMap<VariableId, i64>) -> bool

Evaluates if the constraint is satisfied under a complete or partial variable assignment.

fn is_satisfiable( &self, domains: &HashMap<VariableId, Domain>, _assignment: &HashMap<VariableId, i64>, ) -> bool

Returns false only if this constraint can provably never be satisfied by any completion consistent with the current domains, regardless of how the as-yet-unassigned variables in its scope are eventually assigned.

fn propagate(&self, domains: &mut TrailedDomains) -> PropagationResult

Enforces arc/bounds consistency by pruning inconsistent values from variable domains.

fn violations(&self, assignment: &HashMap<VariableId, i64>) -> u32

How many ways this constraint is broken under assignment, not merely whether it is.

fn explain(&self, assignment: &Assignment) -> Option<Explanation>

Explains a concrete violation, or returns None when the assignment does not violate this constraint or the implementation has no specialized explanation.

fn validate(&self) -> Result<(), String>

Validates the constraint’s own parameters independent of any assignment or domain state.

impl Debug for ExactlyOne

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.