Struct Args 

pub struct Args {
    pub map: HashMap<Ident, Option<Value>>,
}

A parsed set of macro attribute arguments, keyed by argument name.

Fields

map: HashMap<Ident, Option<Value>>

Maps each argument identifier to its optional value (None when the argument was supplied as a bare flag without a value).

Implementations

impl Args

pub fn new() -> Args

Creates an empty set of arguments.

pub fn has(&self, ident: &str) -> bool

Returns true if an argument with the given name is present.

pub fn get(&self, ident: &str) -> Option<&Option<Value>>

Looks up an argument by name, returning its optional value, or None if the argument is not present.

pub fn get_value_or<T: ToTokens>( &self, ident: &str, field: T, msg: &str, ) -> Result<Option<Value>, TokenStream>

Returns the value of ident: Ok(None) if the argument is absent, Ok(Some(_)) if it has a value, or an error spanned over field with msg if the argument is present but carries no value.

pub fn to_string_kv(&self) -> Vec<(String, String)>

Returns the arguments as a list of name/value string pairs, with string literals unquoted and valueless arguments mapped to an empty string.

pub fn allow(&self, list: &[&str]) -> Result<()>

Validates that every argument name present is contained in list, returning an error spanned over the first unsupported argument.

Trait Implementations

impl Debug for Args

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

Formats the value using the given formatter.

impl Default for Args

fn default() -> Self

Returns the “default value” for a type.

impl Parse for Args

fn parse(input: ParseStream<'_>) -> Result<Self>