Enum DoubleDash 

pub enum DoubleDash {
    Optional,
    Required,
    Preserve,
    Automatic,
}

How an argument relates to the -- separator.

Variants

Optional

Values may appear on either side of a --.

Required

Values are accepted only after a --.

Preserve

A -- is kept as a value rather than consumed as a separator.

Automatic

Once the argument takes a value, behave as if a -- had been given, so the rest of the command line is values. A wrapper can then forward flags without its caller typing the separator.

Trait Implementations

impl Clone for DoubleDash

fn clone(&self) -> DoubleDash

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for DoubleDash

impl Debug for DoubleDash

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

Formats the value using the given formatter.

impl Default for DoubleDash

fn default() -> DoubleDash

Returns the “default value” for a type.

impl Eq for DoubleDash

impl PartialEq for DoubleDash

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for DoubleDash