Struct NonEmpty 

pub struct NonEmpty<T> { /* private fields */ }

A collection that cannot be empty.

04-subsystem-contracts.md types the routing token as Option<NonEmpty<Label>>, and the v1 spike shows why the inner non-emptiness is load-bearing rather than tidy: generate-jitconfig with labels: [] returns 422 Invalid property /labels: 1 item required (docs/spikes/d18-org-jit-verification.md, Point 3). An empty label set is not a degenerate case to handle at the gateway; it is a value the domain should not be able to hand out.

crate::policy::RoutingLabels gives a stronger guarantee than this type and is what a policy actually stores; this type is the shape the contract document names, and crate::policy::RoutingLabels::to_non_empty produces it.

Implementations

impl<T> NonEmpty<T>

pub fn of(first: T) -> Self

pub fn try_from_vec( items: Vec<T>, what: &'static str, ) -> Result<Self, ValidationError>

Errors

ValidationError::NonEmptyRequired when items is empty.

pub fn first(&self) -> &T

pub fn count(&self) -> NonZeroUsize

The number of elements. Never zero, which is why this returns NonZeroUsize rather than usize and is not called len.

pub fn iter(&self) -> Iter<'_, T>

pub fn as_slice(&self) -> &[T]

pub fn push(&mut self, item: T)

pub fn into_vec(self) -> Vec<T>

pub fn contains(&self, needle: &T) -> bool

where T: PartialEq,

Trait Implementations

impl<T: Clone> Clone for NonEmpty<T>

fn clone(&self) -> NonEmpty<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for NonEmpty<T>

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

Formats the value using the given formatter.

impl<T: Eq> Eq for NonEmpty<T>

impl<T: Hash> Hash for NonEmpty<T>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<'a, T> IntoIterator for &'a NonEmpty<T>

type Item = &'a T

The type of the elements being iterated over.

type IntoIter = Iter<'a, T>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<T> IntoIterator for NonEmpty<T>

type Item = T

The type of the elements being iterated over.

type IntoIter = IntoIter<T>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<T: Ord> Ord for NonEmpty<T>

fn cmp(&self, other: &NonEmpty<T>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl<T: PartialEq> PartialEq for NonEmpty<T>

fn eq(&self, other: &NonEmpty<T>) -> bool

Equality operator ==.

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

Inequality operator !=.

impl<T: PartialOrd> PartialOrd for NonEmpty<T>

fn partial_cmp(&self, other: &NonEmpty<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T: PartialEq> StructuralPartialEq for NonEmpty<T>