Struct differential_dataflow::difference::Present[][src]

pub struct Present;

A zero-sized difference that indicates the presence of a record.

This difference type has no negation, and present records cannot be retracted. Addition and multiplication maintain presence, and zero does not inhabit the type.

The primary feature of this type is that it has zero size, which reduces the overhead of differential dataflow’s representations for settings where collections either do not change, or for which records are only added (for example, derived facts in Datalog).

Trait Implementations

impl Abomonation for Present[src]

impl<'a> AddAssign<&'a Present> for Present[src]

impl Clone for Present[src]

impl Copy for Present[src]

impl Debug for Present[src]

impl<'de> Deserialize<'de> for Present[src]

impl Eq for Present[src]

impl Hash for Present[src]

impl<T> Mul<T> for Present[src]

type Output = T

The resulting type after applying the * operator.

impl Ord for Present[src]

impl PartialEq<Present> for Present[src]

impl PartialOrd<Present> for Present[src]

impl Semigroup for Present[src]

impl Serialize for Present[src]

impl StructuralEq for Present[src]

impl StructuralPartialEq for Present[src]

Auto Trait Implementations

impl RefUnwindSafe for Present

impl Send for Present

impl Sync for Present

impl Unpin for Present

impl UnwindSafe for Present

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized

impl<T> Borrow<T> for T where
    T: ?Sized

impl<T> BorrowMut<T> for T where
    T: ?Sized

impl<T> Data for T where
    T: Ord + Debug + Data

impl<T> Data for T where
    T: 'static + Send + Sync + Any + Abomonation

impl<T> Data for T where
    T: 'static + Clone

impl<T> DeserializeOwned for T where
    T: for<'de> Deserialize<'de>, 

impl<T> ExchangeData for T where
    T: Ord + Debug + ExchangeData

impl<T> ExchangeData for T where
    T: Data + Data, 

impl<T> From<T> for T[src]

impl<T> Hashable for T where
    T: Hash

type Output = u64

The type of the output value.

impl<T, U> Into<U> for T where
    U: From<T>, 

impl<T> ProgressEventTimestamp for T where
    T: Data + Any + Debug

impl<T> ToOwned for T where
    T: Clone

type Owned = T

The resulting type after obtaining ownership.

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.