Enum QoSDurabilityPolicy 

pub enum QoSDurabilityPolicy {
    SystemDefault,
    Volatile,
    TransientLocal,
    Unknown,
}

QoS durability policy

Variants

SystemDefault

The caller did not state a durability policy — the backend picks. Upstream’s RMW_QOS_POLICY_DURABILITY_SYSTEM_DEFAULT; lowers to NROS_RMW_DURABILITY_SYSTEM_DEFAULT (0) across the C ABI.

See QoSSystemDefaults.

Volatile

Messages are discarded when subscriber disconnects

TransientLocal

Messages are persisted for late-joining subscribers

Unknown

The backend could not determine this policy. Upstream’s RMW_QOS_POLICY_DURABILITY_UNKNOWN; lowers to NROS_RMW_DURABILITY_UNKNOWN (3) across the C ABI.

An ABSENCE, not a value: it is what a *_get_actual_qos read-back writes for a policy it looked at and cannot report, and it is never a request an application makes. Distinct from SystemDefault, which is “nobody asked, so the middleware chooses” — see QoSProfile::QOS_PROFILE_UNKNOWN.

Trait Implementations

impl Clone for QoSDurabilityPolicy

fn clone(&self) -> QoSDurabilityPolicy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for QoSDurabilityPolicy

impl Debug for QoSDurabilityPolicy

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

Formats the value using the given formatter.

impl Default for QoSDurabilityPolicy

fn default() -> QoSDurabilityPolicy

Returns the “default value” for a type.

impl Eq for QoSDurabilityPolicy

impl PartialEq for QoSDurabilityPolicy

fn eq(&self, other: &QoSDurabilityPolicy) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for QoSDurabilityPolicy