Struct MultiTopic 

pub struct MultiTopic<T: DdsType> { /* private fields */ }

MultiTopic<T> — spec §2.2.2.3.4 (DDS 1.4 optional feature).

A MultiTopic combines several underlying topics into a single TopicDescription via a subscription_expression (SQL subset). The resulting type T is user-defined; the underlying topics may have different types.

Cross-topic sample routing: the join operator is live via hash_join_two and Self::evaluate_joined. The subscription_expression references fields as <topic_name>.<field_path> (dotted), and JoinedRow dispatches the lookups to the matching topic sources.

Implementations

impl<T: DdsType> MultiTopic<T>

pub fn get_subscription_expression(&self) -> &str

Spec §2.2.2.3.4.4 get_subscription_expression.

pub fn get_expression_parameters(&self) -> Vec<String>

Spec §2.2.2.3.4.5 get_expression_parameters.

pub fn set_expression_parameters(&self, params: Vec<String>) -> Result<()>

Spec §2.2.2.3.4.6 set_expression_parameters.

Errors

BadParameter if a referenced %N parameter is outside the new vec; PreconditionNotMet on lock poisoning.

pub fn get_related_topic_names(&self) -> &[String]

Spec §2.2.2.3.4.3 get_related_topic (the PSM returns a sequence — we return the names).

pub fn evaluate_joined(&self, row: &JoinedRow<'_>) -> Result<bool>

Evaluates the subscription_expression against a JoinedRow (cross-topic predicate). Spec §2.2.2.3.4.

Errors

PreconditionNotMet on lock poisoning or SQL eval error.

Trait Implementations

impl<T: DdsType> Clone for MultiTopic<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: DdsType> Debug for MultiTopic<T>

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

Formats the value using the given formatter.

impl<T: DdsType> TopicDescription for MultiTopic<T>

fn get_type_name(&self) -> &str

Type name (e.g. "std_msgs::msg::String"). Spec §2.2.2.3.1 get_type_name.

fn get_name(&self) -> &str

Topic name (e.g. "ChatterTopic"). Spec §2.2.2.3.1 get_name.

fn get_participant(&self) -> &DomainParticipant

Owning participant. Spec §2.2.2.3.1 get_participant.