Struct AtMostOne 

pub struct AtMostOne<Id, T>(pub Option<(Id, T)>);

Zero or one value with ID.

Tuple Fields

0: Option<(Id, T)>

Optional (id, value) pair.

Trait Implementations

impl<Id, T> Cardinality<Id, T> for AtMostOne<Id, T>

type Rebind<U> = AtMostOne<Id, U>

Same cardinality with a different inner type.

fn map<N>(&self, map: impl FnMut(&Id, &T) -> N) -> Self::Rebind<N>

where Id: Clone,

Maps values by reference while preserving cardinality.

fn map_mut<N>(self, map: impl FnMut(T) -> N) -> Self::Rebind<N>

Maps values by value while preserving cardinality.

fn get(&self, id: &Id) -> Option<&T>

where Id: Hash + Eq,

Returns the value associated with id, if present.

impl<Id: Clone, T: Clone> Clone for AtMostOne<Id, T>

fn clone(&self) -> AtMostOne<Id, T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<Id: Debug, T: Debug> Debug for AtMostOne<Id, T>

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

Formats the value using the given formatter.

impl<Id: Hash + Eq + Into<Val>> From<AtMostOne<Id, Val>> for Val

fn from(socket: AtMostOne<Id, Val>) -> Self

Converts to this type from the input type.