Enum FoldStateError 

#[non_exhaustive]
pub enum FoldStateError {
    MissingKey,
    DuplicateEntry(MetadataError),
}

An error representing an invalid FoldState

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

MissingKey

The fold state key is missing

DuplicateEntry(MetadataError)

Duplicate entry

Trait Implementations

impl Debug for FoldStateError

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

Formats the value using the given formatter.

impl Display for FoldStateError

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

Formats the value using the given formatter.

impl Error for FoldStateError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

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

Provides type-based access to context intended for error reports.

impl From<MetadataError> for FoldStateError

fn from(source: MetadataError) -> Self

Converts to this type from the input type.