Struct FromMetaOptions

pub struct FromMetaOptions {
    base: Core,
    from_word: Option<Callable>,
    from_none: Option<Callable>,
}

Fields

base: Core

from_word: Option<Callable>

Override for the default FromMeta::from_word method.

from_none: Option<Callable>

Override for the default FromMeta::from_none method.

Implementations

impl FromMetaOptions

pub fn new(di: &DeriveInput) -> Result<Self>

fn from_word(&self) -> Option<Cow<'_, Callable>>

Get the from_word method body, if one exists. This can come from direct use of #[darling(from_word = ...)] on the container or from use of #[darling(word)] on a unit variant.

Trait Implementations

impl<'a> From<&'a FromMetaOptions> for FromMetaImpl<'a>

fn from(v: &'a FromMetaOptions) -> Self

Converts to this type from the input type.

impl ParseAttribute for FromMetaOptions

fn parse_nested(&mut self, mi: &Meta) -> Result<()>

Read a meta-item, and apply its values to the current instance.

fn parse_attributes(self, attrs: &[Attribute]) -> Result<Self>

impl ParseData for FromMetaOptions

fn parse_variant(&mut self, variant: &Variant) -> Result<()>

Apply the next found variant to the object, returning an error if parsing goes wrong.

fn parse_field(&mut self, field: &Field) -> Result<()>

Apply the next found struct field to the object, returning an error if parsing goes wrong.

fn validate_body(&self, errors: &mut Accumulator)

Perform validation checks that require data from more than one field or variant. The default implementation does no validations. Implementors can override this method as appropriate for their use-case.

fn parse_body(self, body: &Data) -> Result<Self>

impl ToTokens for FromMetaOptions

fn to_tokens(&self, tokens: &mut TokenStream)

Write self to the given TokenStream.

fn to_token_stream(&self) -> TokenStream

Convert self directly into a TokenStream object.

fn into_token_stream(self) -> TokenStream

where Self: Sized,

Convert self directly into a TokenStream object.