Struct Ignored

pub struct Ignored;

An efficient way of discarding data from a syntax element.

All syntax elements will be successfully read into the Ignored struct, with all properties discarded.

Trait Implementations

impl Clone for Ignored

fn clone(&self) -> Ignored

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Ignored

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

Formats the value using the given formatter.

impl Default for Ignored

fn default() -> Ignored

Returns the “default value” for a type.

impl FromDeriveInput for Ignored

fn from_derive_input(_: &DeriveInput) -> Result<Ignored, Error>

Create an instance from syn::DeriveInput, or return an error.

impl FromField for Ignored

fn from_field(_: &Field) -> Result<Ignored, Error>

impl FromGenericParam for Ignored

fn from_generic_param(_: &GenericParam) -> Result<Ignored, Error>

impl FromGenerics for Ignored

fn from_generics(_: &Generics) -> Result<Ignored, Error>

impl FromMeta for Ignored

fn from_meta(_: &Meta) -> Result<Ignored, Error>

Create an instance from a syn::Meta by dispatching to the format-appropriate trait function. This generally should not be overridden by implementers.

fn from_nested_meta(item: &NestedMeta) -> Result<Self, Error>

fn from_none() -> Option<Self>

When a field is omitted from a parent meta-item, from_none is used to attempt recovery before a missing field error is generated.

fn from_word() -> Result<Self, Error>

Create an instance from the presence of the word in the attribute with no additional options specified.

fn from_list(items: &[NestedMeta]) -> Result<Self, Error>

Create an instance from a list of nested meta items.

fn from_value(value: &Lit) -> Result<Self, Error>

Create an instance from a literal value of either foo = "bar" or foo("bar"). This dispatches to the appropriate method based on the type of literal encountered, and generally should not be overridden by implementers.

fn from_expr(expr: &Expr) -> Result<Self, Error>

fn from_char(value: char) -> Result<Self, Error>

Create an instance from a char literal in a value position.

fn from_string(value: &str) -> Result<Self, Error>

Create an instance from a string literal in a value position.

fn from_bool(value: bool) -> Result<Self, Error>

Create an instance from a bool literal in a value position.

impl FromTypeParam for Ignored

fn from_type_param(_: &TypeParam) -> Result<Ignored, Error>

impl FromVariant for Ignored

fn from_variant(_: &Variant) -> Result<Ignored, Error>

Create an instance from syn::Variant, or return an error.

impl Hash for Ignored

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Ignored

fn eq(&self, other: &Ignored) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl UsesLifetimes for Ignored

fn uses_lifetimes<'a>( &self, _opts: &Options, _: &'a HashSet<Lifetime, BuildHasherDefault<FnvHasher>>, ) -> HashSet<&'a Lifetime, BuildHasherDefault<FnvHasher>>

Returns the subset of the queried lifetimes that are used by the implementing syntax element.

fn uses_lifetimes_cloned( &self, options: &Options, lifetimes: &HashSet<Lifetime, BuildHasherDefault<FnvHasher>>, ) -> HashSet<Lifetime, BuildHasherDefault<FnvHasher>>

Find all used lifetimes, then clone them and return that set.

impl UsesTypeParams for Ignored

fn uses_type_params<'a>( &self, _opts: &Options, _: &'a HashSet<Ident, BuildHasherDefault<FnvHasher>>, ) -> HashSet<&'a Ident, BuildHasherDefault<FnvHasher>>

Returns the subset of the queried type parameters that are used by the implementing syntax element.

fn uses_type_params_cloned( &self, options: &Options, type_set: &HashSet<Ident, BuildHasherDefault<FnvHasher>>, ) -> HashSet<Ident, BuildHasherDefault<FnvHasher>>

Find all type params using uses_type_params, then clone the found values and return the set.

impl Copy for Ignored

impl Eq for Ignored

impl StructuralPartialEq for Ignored