Enum Void 

pub enum Void {}

The Void type, a.k.a. θ, is used to represent the end of an anonymous sum type, or an empty sum type.

Void is commonly used as the Tail of a Either type, to terminate the list. When used on its own, it represents an empty sum type, which can never be constructed.

Void is functionally the same as the never type, !, or otherwise Infallible. However, we define a separate Void type, to make it more clear that it is specifically used for terminating a sum type.

Read more about sum types in Either.

Trait Implementations

impl Clone for θ

fn clone(&self) -> θ

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for θ

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

Formats the value using the given formatter.

impl<Source, Target> FieldsExtractor<Source, Target> for θ

type Remainder = Source

fn extract_from(source: Source) -> Result<Target, Source>

impl FinalizeExtract for θ

fn finalize_extract<T>(self) -> T

impl<Mapper> MapFields<Mapper> for θ

type Mapped = θ

impl PartialEq for θ

fn eq(&self, other: &θ) -> 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 Eq for θ

impl StructuralPartialEq for θ