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

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pub fn is_word(&self) -> bool

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

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

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

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fn from_tokens<'a, I>(tokens: &mut Peekable<I>) -> Option<MetaItem>
where I: Iterator<Item = &'a 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
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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: SpanDecoder> Decodable<__D> for MetaItem

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

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

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

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impl<__CTX> HashStable<__CTX> for MetaItem
where __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> Aligned for T

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const ALIGN: Alignment = _

Alignment of Self.
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impl<T> Any for T
where 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 T
where T: ?Sized,

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fn borrow(&self) -> &T

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

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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

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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impl<T, U> Into<U> for T
where U: From<T>,

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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> Pointable for T

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const ALIGN: usize = _

The alignment of pointer.
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type Init = T

The type for initializers.
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unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
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unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
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unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
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unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
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impl<T> Same for T

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type Output = T

Should always be Self
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impl<T> ToOwned for T
where 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 T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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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 T
where U: TryFrom<T>,

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

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<T> WithSubscriber for T

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fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
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fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more
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impl<'a, T> Captures<'a> for T
where T: ?Sized,

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