use ;
/// Common contract for values that can validate their own invariants.
///
/// Implementations should be deterministic and side-effect-free. Validation
/// reports whether the value satisfies its documented contract; it does not
/// promise that later operations will succeed if external conditions change.
/// Contract for values that expose a stable, non-zero Core identifier.
///
/// Implementors must return the same identifier for the lifetime of the value.
/// The trait does not allocate IDs, establish global uniqueness, or imply that
/// the implementing value is registered with a runtime.