Trait ValueEnum 

pub trait ValueEnum: Sized + 'static {
    const VARIANTS: &'static [Self];
    const POSSIBLE_VALUES: &'static [&'static str];

    // Required methods
    fn value_name(&self) -> &'static str;
    fn from_value(value: &str) -> Option<Self>;
}

An enum whose variants are the accepted values of an argument.

Usually implemented with #[derive(ValueEnum)]. Fields of a ValueEnum type marked with #[arg(value_enum)] are parsed with from_value and list their POSSIBLE_VALUES in the generated help.

Required Associated Constants

const VARIANTS: &'static [Self]

Every variant, in declaration order.

const POSSIBLE_VALUES: &'static [&'static str]

The name of every variant, in declaration order, as accepted on the command line and shown in the generated help. Aliases are not included.

Required Methods

fn value_name(&self) -> &'static str

Returns the name of this variant, as listed in POSSIBLE_VALUES.

fn from_value(value: &str) -> Option<Self>

Returns the variant whose name or alias is exactly value, if any.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors