Struct WithNull 

pub struct WithNull<R>(pub R);

Wraps a host registry so that null is always available.

Tuple Fields

0: R

Trait Implementations

impl<R: Clone> Clone for WithNull<R>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<R: DatamodelRegistry> DatamodelRegistry for WithNull<R>

fn create(&self, name: &str) -> Option<Box<dyn Datamodel>>

A fresh datamodel instance for name, or None when it is not registered.

fn create_for( &self, chart: &Chart, ) -> Option<Result<Box<dyn Datamodel>, Vec<String>>>

A fresh datamodel instance for chart, prepared from the whole chart: None when the chart’s datamodel is not registered, and Some(Err(problems)) when the datamodel refuses to instantiate the chart (a statically checked datamodel refuses a chart with type errors). The default creates the datamodel by name and refuses nothing.

fn check(&self, chart: &Chart) -> Result<(), Vec<String>>

Every reason the chart’s datamodel would refuse to instantiate chart (as DatamodelRegistry::create_for would), without creating an instance; hosts call it when a chart is registered. The default refuses nothing.

impl<R: Debug> Debug for WithNull<R>

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

Formats the value using the given formatter.

impl<R: Default> Default for WithNull<R>

fn default() -> Self

Returns the “default value” for a type.