Trait clap::ArgEnum [−][src]
pub trait ArgEnum: Sized + Clone {
fn value_variants<'a>() -> &'a [Self]ⓘ;
fn to_possible_value<'a>(&self) -> Option<PossibleValue<'a>>;
fn from_str(input: &str, ignore_case: bool) -> Result<Self, String> { ... }
}
Expand description
Parse arguments into enums.
When deriving Parser
, a field whose type implements ArgEnum
can have the attribute
#[clap(arg_enum)]
. In addition to parsing, help and error messages may report possible
variants.
Example
#[derive(clap::Parser)]
struct Args {
#[clap(arg_enum)]
level: Level,
}
#[derive(clap::ArgEnum, Clone)]
enum Level {
Debug,
Info,
Warning,
Error,
}
Required methods
All possible argument values, in display order.
fn to_possible_value<'a>(&self) -> Option<PossibleValue<'a>>
fn to_possible_value<'a>(&self) -> Option<PossibleValue<'a>>
The canonical argument value.
The value is None
for skipped variants.