Enum CuLatchedStateUpdate 

pub enum CuLatchedStateUpdate<T: Clone> {
    NoChange,
    Set(T),
    Clear,
}

Producer-side update for a stateful value cached by downstream consumers.

Use this when a value is logically “sticky” across cycles, but you still want its evolution to be explicit in the message stream. A typical producer pattern is:

• emit Self::Set when the value first becomes available or changes
• emit Self::NoChange on cycles where the previously latched value remains valid
• emit Self::Clear when the cached value must be invalidated

Each consumer that cares about the value should keep a local CuLatchedState and apply incoming updates to it. Copper does not implicitly retain or replay the previous payload for you; the state transition is part of the payload itself.

NoChange is intentionally the first variant so its bincode discriminant is zero.

Examples

use cu29_runtime::payload::{CuLatchedState, CuLatchedStateUpdate};

let mut calibration = CuLatchedState::default();

calibration.update(&CuLatchedStateUpdate::Set(42u32));
assert_eq!(calibration.get(), Some(&42));

calibration.update(&CuLatchedStateUpdate::NoChange);
assert_eq!(calibration.get(), Some(&42));

calibration.update_owned(CuLatchedStateUpdate::Clear);
assert!(calibration.is_unset());

Variants

NoChange

Leave the consumer-side cache unchanged for this cycle.

Set(T)

Replace the consumer-side cache with a new value.

Clear

Remove the consumer-side cached value.

Implementations

impl<T: Clone> CuLatchedStateUpdate<T>

pub fn is_no_change(&self) -> bool

Returns true when this update leaves the cached value unchanged.

pub fn is_set(&self) -> bool

Returns true when this update carries a replacement value.

pub fn is_clear(&self) -> bool

Returns true when this update clears the cached value.

Trait Implementations

impl<'__de, T, __Context> BorrowDecode<'__de, __Context> for CuLatchedStateUpdate<T>

where T: BorrowDecode<'__de, __Context> + Clone,

fn borrow_decode<__D: BorrowDecoder<'__de, Context = __Context>>( decoder: &mut __D, ) -> Result<Self, DecodeError>

Attempt to decode this type with the given BorrowDecode.

impl<T: Clone + Clone> Clone for CuLatchedStateUpdate<T>

fn clone(&self) -> CuLatchedStateUpdate<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug + Clone> Debug for CuLatchedStateUpdate<T>

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

Formats the value using the given formatter.

impl<T, __Context> Decode<__Context> for CuLatchedStateUpdate<T>

where T: Decode<__Context> + Clone,

fn decode<__D: Decoder<Context = __Context>>( decoder: &mut __D, ) -> Result<Self, DecodeError>

Attempt to decode this type with the given Decode.

impl<T: Clone> Default for CuLatchedStateUpdate<T>

fn default() -> CuLatchedStateUpdate<T>

Returns the “default value” for a type.

impl<'de, T> Deserialize<'de> for CuLatchedStateUpdate<T>

where T: Deserialize<'de> + Clone,

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<T> Encode for CuLatchedStateUpdate<T>

where T: Encode + Clone,

fn encode<__E: Encoder>(&self, encoder: &mut __E) -> Result<(), EncodeError>

Encode a given type.

impl<T: Clone> From<T> for CuLatchedStateUpdate<T>

fn from(value: T) -> Self

Converts to this type from the input type.

impl<T: PartialEq + Clone> PartialEq for CuLatchedStateUpdate<T>

fn eq(&self, other: &CuLatchedStateUpdate<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T> Serialize for CuLatchedStateUpdate<T>

where T: Serialize + Clone,

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl<T: Clone> TypePath for CuLatchedStateUpdate<T>

fn type_path() -> &'static str

fn short_type_path() -> &'static str

fn type_ident() -> Option<&'static str>

fn crate_name() -> Option<&'static str>

fn module_path() -> Option<&'static str>

impl<T: Clone> StructuralPartialEq for CuLatchedStateUpdate<T>