Struct ErrorMetadata 

pub struct ErrorMetadata { /* private fields */ }

Typed structured metadata attached to an error context.

Unlike OperationContext::with_field and OperationContext::record, whose entries appear in the error’s Display output, metadata stored here is not visible in terminal output. It is intended for programmatic consumers: serialization, snapshots, structured logs, and API responses.

Supports String, bool, i64, and u64 values via MetadataValue.

Implementations

impl ErrorMetadata

pub fn new() -> Self

Create an empty metadata container.

pub fn is_empty(&self) -> bool

Returns true if no entries are stored.

pub fn as_map(&self) -> &BTreeMap<String, MetadataValue>

Borrow the underlying map for read-only access.

pub fn insert<K, V>(&mut self, key: K, value: V)

where K: Into<String>, V: Into<MetadataValue>,

Insert a key-value pair into the metadata.

Supports any key type that converts into String and any value type that converts into MetadataValue (i.e. String, bool, i64, u64, and their subtypes).

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

Look up a key and return its typed value.

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

Look up a key and return its &str value, or None if the key is absent or the value is not a string variant.

pub fn iter(&self) -> impl Iterator<Item = (&String, &MetadataValue)>

Iterate over all key-value pairs.

pub fn merge_missing(&mut self, other: &ErrorMetadata)

Merge entries from other, keeping existing values.

For each key in other, the value is only inserted if the key does not already exist in self. This implements an inner/first wins strategy useful when merging layered metadata where earlier layers should take priority.

See StructError::context_metadata() for a usage example.

Trait Implementations

impl Clone for ErrorMetadata

fn clone(&self) -> ErrorMetadata

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ErrorMetadata

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

Formats the value using the given formatter.

impl Default for ErrorMetadata

fn default() -> ErrorMetadata

Returns the “default value” for a type.

impl PartialEq for ErrorMetadata

fn eq(&self, other: &ErrorMetadata) -> 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 ErrorMetadata

impl StructuralPartialEq for ErrorMetadata