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.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 64 bytes

Size for each variant:

• Downcast: 64 bytes
• UnknownArgument: 0 bytes