Enum Nargs 

pub enum Nargs {
    Count(usize),
    Variadic,
    Optional,
}

Specifies how many arguments a parameter consumes.

This enum corresponds to Python Click’s nargs parameter:

• Count(1) is the default (single value)
• Variadic corresponds to nargs=-1
• Optional corresponds to nargs=? (zero or one value)

Variants

Count(usize)

Exactly N values (default is 1).

Variadic

Zero or more values (Python’s nargs=-1). All remaining arguments are collected.

Optional

Optional single value (Python’s nargs=?). Zero or one value; if not provided, uses the default.

Implementations

impl Nargs

pub fn is_single(&self) -> bool

Returns true if this nargs expects exactly one value.

pub fn is_multi(&self) -> bool

Returns true if this nargs can accept multiple values.

pub fn is_variadic(&self) -> bool

Returns true if this nargs accepts zero or more values.

pub fn is_optional(&self) -> bool

Returns true if this nargs is optional (zero or one).

pub fn count(&self) -> Option<usize>

Returns the exact count if this is Count(n), otherwise None.

Trait Implementations

impl Clone for Nargs

fn clone(&self) -> Nargs

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Nargs

impl Debug for Nargs

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

Formats the value using the given formatter.

impl Default for Nargs

fn default() -> Self

Returns the “default value” for a type.

impl Display for Nargs

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

Formats the value using the given formatter.

impl Eq for Nargs

impl Hash for Nargs

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 Nargs

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