Struct ArgMeta 

pub struct ArgMeta<'a> { /* private fields */ }

What a positional argument knows about itself beyond how it parses.

Read it through the accessor methods. The fields are pub only because derived code builds this struct with a literal in the adopter’s crate; they are hidden from the docs because how they are laid out is not part of the API.

Implementations

impl ArgMeta<'_>

pub const EMPTY: ArgMeta<'static>

Metadata for an argument with nothing declared, for struct update syntax.

impl<'a> ArgMeta<'a>

Read access to every field, wherever it is stored.

Prefer these to the fields: the fields are laid out for table size and may move behind a cold extra half the way FlagMeta’s did in 6.11.1, and a getter keeps its name and type when that happens.

pub const fn arg(&self) -> &'a Arg<'a>

pub const fn display_order(&self) -> Option<u32>

Explicit placement within its help section.

pub const fn value_names(&self) -> &'a [&'a str]

Ordered placeholders for a fixed-arity positional.

pub const fn help(&self) -> Option<&'a str>

pub const fn long_help(&self) -> Option<&'a str>

pub const fn admonitions(&self) -> &'a [AdmonitionMeta<'a>]

Notes and warnings shown after the extended help text.

pub const fn env(&self) -> Option<&'a str>

pub const fn env_fallback(&self) -> &'a [&'a str]

pub const fn deprecated_env(&self) -> &'a [&'a str]

pub const fn default(&self) -> &'a [&'a str]

pub const fn accepted_choices(&self) -> &'a [&'a str]

Canonical choices plus aliases accepted by the value type.

pub const fn choices(&self) -> &'a [&'a str]

pub const fn choice_aliases(&self) -> &'a [(&'a str, &'a str)]

Canonical-to-alias pairs used when emitting a lossless spec.

pub const fn choice_details(&self) -> &'a [ChoiceMeta<'a>]

Per-canonical presentation metadata used when emitting a lossless spec.

pub const fn ignore_case(&self) -> bool

pub const fn allow_unknown_choices(&self) -> bool

Accept values outside choices while retaining the list for help and completion.

pub const fn validate(&self) -> Option<&'a str>

Portable expr expression evaluated for each raw value.

pub const fn validate_error(&self) -> Option<&'a str>

Message reported when validation returns false.

pub const fn required(&self) -> bool

Whether the argument must be filled. The parser does not enforce this — it is checked once the last token has been read — but the spec has to say it, and help output has to show it.

pub const fn hide(&self) -> bool

pub const fn hide_default_value(&self) -> bool

pub const fn hide_env(&self) -> bool

pub const fn hide_env_values(&self) -> bool

pub const fn hide_possible_values(&self) -> bool

pub const fn hide_short_help(&self) -> bool

pub const fn hide_long_help(&self) -> bool

pub const fn conflicts(&self) -> &'a [&'a str]

Entries that cannot be given alongside this positional.

pub const fn requires(&self) -> &'a [&'a str]

pub const fn required_if(&self) -> &'a [&'a str]

pub const fn required_if_eq(&self) -> &'a [RequiredIfEq<'a>]

pub const fn required_if_eq_all(&self) -> &'a [RequiredIfEq<'a>]

pub const fn required_unless(&self) -> &'a [&'a str]

pub const fn required_unless_all(&self) -> &'a [&'a str]

pub const fn var_min(&self) -> Option<u32>

pub const fn var_max(&self) -> Option<u32>

pub const fn delimiter(&self) -> Option<char>

The character one word is split on to make several positional values.

pub const fn help_heading(&self) -> Option<&'a str>

Heading to list this argument under in help output.

pub const fn surface(&self) -> Option<&'a str>

Named audience or compatibility surface this argument belongs to.

pub const fn available_if(&self) -> &'a [&'a str]

Descriptive availability conditions; they do not affect parsing.

pub const fn complete( &self, ) -> Option<fn(&CompleteCtx<'_>) -> Vec<Candidate<'static>>>

What answers for this argument when a shell asks. See FlagMeta::complete.

pub const fn complete_type(&self) -> Option<&'a str>

A built-in completion class such as path or dir.

Trait Implementations

impl<'a> Clone for ArgMeta<'a>

fn clone(&self) -> ArgMeta<'a>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Copy for ArgMeta<'a>

impl<'a> Debug for ArgMeta<'a>

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

Formats the value using the given formatter.