Enum InterfaceCardinality 

pub enum InterfaceCardinality {
    AtMostOne,
    ExactlyOne,
    AtLeastOne,
    Any,
}

Specifies how many plugins may or must implement an interface.

Cardinality expresses what the consumer of an interface expects:

• ExactlyOne: The consumer expects a single implementation. Dispatch returns a single value directly.

• AtMostOne: The consumer can work with zero or one implementation. Dispatch returns an Option.

• AtLeastOne: The consumer requires at least one implementation but can handle multiple. Dispatch returns a collection.

• Any: The consumer doesn’t care how many implementations exist (including zero). Dispatch returns a collection. Useful for optional extension points.

The cardinality determines the Socket variant used at runtime and affects how dispatch results are wrapped.

Variants

AtMostOne

Zero or one plugin allowed. Dispatch returns Option<T>.

ExactlyOne

Exactly one plugin required. Dispatch returns T directly.

AtLeastOne

One or more plugins required. Dispatch returns a collection.

Any

Zero or more plugins allowed. Dispatch returns a collection.

Trait Implementations

impl Clone for InterfaceCardinality

fn clone(&self) -> InterfaceCardinality

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for InterfaceCardinality

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

Formats the value using the given formatter.

impl Display for InterfaceCardinality

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

Formats the value using the given formatter.

impl PartialEq for InterfaceCardinality

fn eq(&self, other: &InterfaceCardinality) -> 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 Copy for InterfaceCardinality

impl Eq for InterfaceCardinality

impl StructuralPartialEq for InterfaceCardinality