Struct Navigation 

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

Marker value for a single related entity navigation.

Navigation fields are not persisted as columns. They exist so #[derive(Entity)] can attach navigation metadata to the entity while future loading APIs decide explicitly when related rows are fetched.

Implementations

impl<T> Navigation<T>

pub const fn empty() -> Self

Creates an empty navigation value.

pub fn loaded(value: T) -> Self

Creates a navigation value containing a loaded related entity.

pub fn from_option(value: Option<T>) -> Self

Creates a navigation value from an optional related entity.

pub fn as_ref(&self) -> Option<&T>

Returns the loaded related entity when one has been attached.

pub fn set(&mut self, value: Option<T>)

Replaces the loaded related entity.

Trait Implementations

impl<T: Clone> Clone for Navigation<T>

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

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for Navigation<T>

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

Formats the value using the given formatter.

impl<T> Default for Navigation<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T: PartialEq> PartialEq for Navigation<T>

fn eq(&self, other: &Navigation<T>) -> 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<T: Eq> Eq for Navigation<T>

impl<T> StructuralPartialEq for Navigation<T>