Enum MatchesError

#[non_exhaustive]
pub enum MatchesError {
    Downcast {
        actual: AnyValueId,
        expected: AnyValueId,
    },
    UnknownArgument {},
}

Violation of ArgMatches assumptions

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.

Downcast

Failed to downcast AnyValue to the specified type

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

actual: AnyValueId

Type for value stored in ArgMatches

expected: AnyValueId

The target type to downcast to

UnknownArgument

Argument not defined in Command

Trait Implementations

impl Clone for MatchesError

fn clone(&self) -> MatchesError

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for MatchesError

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

Formats the value using the given formatter.

impl Display for MatchesError

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

Formats the value using the given formatter.

impl Error for MatchesError

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.