Struct Metadata 

pub struct Metadata { /* private fields */ }

Typed metadata map validated against a MetadataSchema.

Implementations

impl Metadata

pub fn new(schema: &MetadataSchema) -> Self

Creates metadata map with every core key pre-populated as None.

pub fn get(&self, key: &str) -> Option<&MetadataValue>

Returns metadata value by key.

pub fn clear(&mut self, schema: &MetadataSchema, key: &str) -> Result<()>

Clears registered metadata key by writing None.

pub fn iter(&self) -> impl Iterator<Item = (&str, &MetadataValue)> + '_

Iterates metadata entries in deterministic key order.

pub fn set( &mut self, schema: &MetadataSchema, key: &str, value: MetadataValue, ) -> Result<()>

Writes metadata value after registration and type validation.

Trait Implementations

impl Clone for Metadata

fn clone(&self) -> Metadata

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Metadata

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

Formats the value using the given formatter.

impl PartialEq for Metadata

fn eq(&self, other: &Metadata) -> 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 StructuralPartialEq for Metadata