Struct rustc_ast::ast::MetaItem

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pub struct MetaItem {
    pub path: Path,
    pub kind: MetaItemKind,
    pub span: Span,
}
Expand description

A semantic representation of a meta item. A meta item is a slightly restricted form of an attribute – it can only contain expressions in certain leaf positions, rather than arbitrary token streams – that is used for most built-in attributes.

E.g., #[test], #[derive(..)], #[rustfmt::skip] or #[feature = "foo"].

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§path: Path§kind: MetaItemKind§span: Span

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impl MetaItem

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pub fn ident(&self) -> Option<Ident>

For a single-segment meta item, returns its name; otherwise, returns None.

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pub fn name_or_empty(&self) -> Symbol

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pub fn name_value_literal(&self) -> Option<&MetaItemLit>

Example:
    #[attribute(name = "value")]
                ^^^^^^^^^^^^^^
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pub fn value_str(&self) -> Option<Symbol>

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pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]>

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pub fn is_word(&self) -> bool

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pub fn has_name(&self, name: Symbol) -> bool

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pub fn name_value_literal_span(&self) -> Option<Span>

This is used in case you want the value span instead of the whole attribute. Example:

#[doc(alias = "foo")]

In here, it’ll return a span for "foo".

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impl MetaItem

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fn from_tokens<I>(tokens: &mut Peekable<I>) -> Option<MetaItem>where
I: Iterator<Item = TokenTree>,

Trait Implementations§

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impl Clone for MetaItem

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fn clone(&self) -> MetaItem

Returns a copy of the value. Read more
1.0.0 · source§

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

Performs copy-assignment from source. Read more
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impl Debug for MetaItem

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

Formats the value using the given formatter. Read more
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impl<__D: Decoder> Decodable<__D> for MetaItem

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fn decode(__decoder: &mut __D) -> Self

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impl<__E: Encoder> Encodable<__E> for MetaItem

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fn encode(&self, __encoder: &mut __E)

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impl<__CTX> HashStable<__CTX> for MetaItemwhere
__CTX: HashStableContext,

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fn hash_stable(&self, __hcx: &mut __CTX, __hasher: &mut StableHasher)

Auto Trait Implementations§

Blanket Implementations§

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impl<T> Any for Twhere
T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere
T: ?Sized,

const: unstable · source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere
T: ?Sized,

const: unstable · source§

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

const: unstable · source§

fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for Twhere
U: From<T>,

const: unstable · source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> ToOwned for Twhere
T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for Twhere
U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
const: unstable · source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere
U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
const: unstable · source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.

Layout§

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference’s “Type Layout” chapter for details on type layout guarantees.

Size: 72 bytes