Enum ErrorKind 

#[non_exhaustive]
pub enum ErrorKind {
    Backtrack,
    UnknownFlag,
    UnexpectedArg,
    MissingValue,
    UnexpectedValue,
    MissingRequired,
    MissingArgument,
    MissingSubcommand,
    Conflict,
    MissingOneOf,
    RequiresDoubleDash,
    HelpRequested,
    VersionRequested,
    InvalidValue,
    InvalidChoice,
}

The class of failure.

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.

Backtrack

A parser did not match here; another one may.

UnknownFlag

A flag-like word matched no flag.

UnexpectedArg

A word nothing could hold.

MissingValue

A flag needing a value did not get one.

UnexpectedValue

A flag that takes no value was given one: --verbose=yes.

MissingRequired

A required flag never appeared.

MissingArgument

A required positional argument was never filled.

MissingSubcommand

A required subcommand was not given.

Conflict

Two arguments that exclude each other were both given.

MissingOneOf

A required group had none of its members.

RequiresDoubleDash

A word reached an argument that only takes words after --.

HelpRequested

-h/--help, or a bare invocation of an arg_required_else_help command: show Error::render_help rather than report a failure.

VersionRequested

-V/--version: show Error::version_text.

InvalidValue

A value that its type rejected.

InvalidChoice

A value outside a fixed set.

Trait Implementations

impl Clone for ErrorKind

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ErrorKind

impl Debug for ErrorKind

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

Formats the value using the given formatter.

impl Eq for ErrorKind

impl Hash for ErrorKind

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ErrorKind

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for ErrorKind