Enum Cardinality 

#[non_exhaustive]
pub enum Cardinality {
    Optional,
    Required,
    Repeated,
}

Field cardinality (proto label).

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Optional

optional (the proto3 default and proto2 explicit optional).

Required

required — proto2 only.

Repeated

repeated.

Trait Implementations

impl Clone for Cardinality

fn clone(&self) -> Cardinality

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Cardinality

impl Debug for Cardinality

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

Formats the value using the given formatter.

impl Eq for Cardinality

impl PartialEq for Cardinality

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Cardinality