Enum Fail

pub enum Fail {
    ArgumentMissing(String),
    UnrecognizedOption(String),
    OptionMissing(String),
    OptionDuplicated(String),
    UnexpectedArgument(String),
}

The type returned when the command line does not conform to the expected format. Use the Debug implementation to output detailed information.

Variants

ArgumentMissing(String)

The option requires an argument but none was passed.

UnrecognizedOption(String)

The passed option is not declared among the possible options.

OptionMissing(String)

A required option is not present.

OptionDuplicated(String)

A single occurrence option is being used multiple times.

UnexpectedArgument(String)

There’s an argument being passed to a non-argument option.

Trait Implementations

impl Clone for Fail

fn clone(&self) -> Fail

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Fail

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

Formats the value using the given formatter.

impl Display for Fail

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

Formats the value using the given formatter.

impl Eq for Fail

#[doc(hidden)] fn assert_receiver_is_total_eq(&self)

impl Error for Fail

fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()

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

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

#[doc(hidden)] fn type_id(&self, _: Internal) -> TypeId

where Self: 'static,

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

Gets the TypeId of self.

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 PartialEq for Fail

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