## Attribute

# Enum Attribute

Source

    pub enum Attribute {
        Parsed(AttributeKind),
        Unparsed(Box<AttrItem>),
    }

## Variants§

§

### Parsed(AttributeKind)

A parsed built-in attribute.

Each attribute has a span connected to it. However, you must be somewhat careful using it. That’s because sometimes we merge multiple attributes together, like when an item has multiple `repr` attributes. In this case the span might not be very useful.

§

### Unparsed(Box<AttrItem>)

An attribute that could not be parsed, out of a token-like representation. This is the case for custom tool attributes.

## Implementations§

Source§

### impl Attribute

Source

#### pub fn get_normal_item(&self) -> &AttrItem

Source

#### pub fn unwrap_normal_item(self) -> AttrItem

Source

#### pub fn value_lit(&self) -> Option<&MetaItemLit>

Source

#### pub fn is_parsed_attr(&self) -> bool

Source§

### impl Attribute

Source

#### pub fn id(&self) -> AttrId

Source

#### pub fn name(&self) -> Option<Symbol>

Source

#### pub fn meta_item_list(&self) -> Option<ThinVec<MetaItemInner>>

Source

#### pub fn value_str(&self) -> Option<Symbol>

Source

#### pub fn value_span(&self) -> Option<Span>

Source

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

Source

#### pub fn path_matches(&self, name: &[Symbol]) -> bool

Source

#### pub fn is_doc_comment(&self) -> Option<Span>

Source

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

Source

#### pub fn has_any_name(&self, names: &[Symbol]) -> bool

Source

#### pub fn span(&self) -> Span

Source

#### pub fn is_word(&self) -> bool

Source

#### pub fn path(&self) -> SmallVec<[Symbol; 1]>

Source

#### pub fn ident_path(&self) -> Option<SmallVec<[Ident; 1]>>

Source

#### pub fn doc_str(&self) -> Option<Symbol>

Source

#### pub fn is_proc_macro_attr(&self) -> bool

Source

#### pub fn doc_str_and_comment_kind(&self) -> Option<(Symbol, CommentKind)>

## Trait Implementations§

Source§

### impl<'tcx> ArenaAllocatable<'tcx> for Attribute

Source§

#### fn allocate_on(self, arena: &'tcx Arena<'tcx>) -> &'tcx mut Self

Source§

#### fn allocate_from_iter( arena: &'tcx Arena<'tcx>, iter: impl IntoIterator<Item = Self>, ) -> &'tcx mut [Self]

Source§

### impl AttributeExt for Attribute

Source§

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

For a single-segment attribute, returns its name; otherwise, returns `None`.

Source§

#### fn id(&self) -> AttrId

Source§

#### fn meta_item_list(&self) -> Option<ThinVec<MetaItemInner>>

Get the meta item list, `#[attr(meta item list)]`
Source§

#### fn value_str(&self) -> Option<Symbol>

Gets the value literal, as string, when using `#[attr = value]`
Source§

#### fn value_span(&self) -> Option<Span>

Gets the span of the value literal, as string, when using `#[attr = value]`
Source§

#### fn path_matches(&self, name: &[Symbol]) -> bool

Checks whether the path of this attribute matches the name. Read more
Source§

#### fn is_doc_comment(&self) -> Option<Span>

Returns `true` if it is a sugared doc comment (`///` or `//!` for example). So `#[doc = "doc"]` (which is a doc comment) and `#[doc(...)]` (which is not a doc comment) will return `false`.
Source§

#### fn span(&self) -> Span

get the span of the entire attribute
Source§

#### fn is_word(&self) -> bool

Source§

#### fn ident_path(&self) -> Option<SmallVec<[Ident; 1]>>

Returns None for doc comments
Source§

#### fn doc_str(&self) -> Option<Symbol>

Returns the documentation if this is a doc comment or a sugared doc comment. Read more
Source§

#### fn is_automatically_derived_attr(&self) -> bool

Source§

#### fn doc_str_and_comment_kind(&self) -> Option<(Symbol, CommentKind)>

Returns the documentation and its kind if this is a doc comment or a sugared doc comment. Read more
Source§

#### fn doc_resolution_scope(&self) -> Option<AttrStyle>

Returns outer or inner if this is a doc attribute or a sugared doc comment, otherwise None. Read more
Source§

#### fn is_proc_macro_attr(&self) -> bool

Source§

#### fn name(&self) -> Option<Symbol>

For a single-segment attribute (i.e., `#[attr]` and not `#[path::atrr]`), return the name of the attribute; otherwise, returns `None`.
Source§

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

Source§

#### fn has_any_name(&self, names: &[Symbol]) -> bool

Source§

#### fn path(&self) -> SmallVec<[Symbol; 1]>

Source§

### impl Clone for Attribute

Source§

#### fn clone(&self) -> Attribute

Returns a duplicate of the value. Read more
1.0.0 · Source§

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

Performs copy-assignment from `source`. Read more
Source§

### impl Debug for Attribute

Source§

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

Formats the value using the given formatter. Read more
Source§

### impl<__D: SpanDecoder> Decodable<__D> for Attribute

Source§

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

Source§

### impl<__E: SpanEncoder> Encodable<__E> for Attribute

Source§

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

Source§

### impl<__CTX> HashStable<__CTX> for Attribute
where __CTX: HashStableContext,

Source§

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

## Auto Trait Implementations§

§

### impl DynSend for Attribute

§

### impl DynSync for Attribute

§

### impl Freeze for Attribute

§

### impl RefUnwindSafe for Attribute

§

### impl Send for Attribute

§

### impl Sync for Attribute

§

### impl Unpin for Attribute

§

### impl UnwindSafe for Attribute

## Blanket Implementations§

Source§

### impl<T> Aligned for T

Source§

#### const ALIGN: Alignment

Alignment of `Self`.
Source§

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

Source§

#### fn type_id(&self) -> TypeId

Gets the `TypeId` of `self`. Read more
Source§

### impl<T> Borrow<T> for T
where T: ?Sized,

Source§

#### fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
Source§

### impl<T> BorrowMut<T> for T
where T: ?Sized,

Source§

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

Mutably borrows from an owned value. Read more
Source§

### impl<T> CloneToUninit for T
where T: Clone,

Source§

#### unsafe fn clone_to_uninit(&self, dest: *mut u8)

🔬This is a nightly-only experimental API. (`clone_to_uninit`)
Performs copy-assignment from `self` to `dest`. Read more
Source§

### impl<T> DynClone for T
where T: Clone,

Source§

#### fn __clone_box(&self, _: Private) -> *mut ()

Source§

### impl<T> From<T> for T

Source§

#### fn from(t: T) -> T

Returns the argument unchanged.

Source§

### impl<T> Instrument for T

Source§

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

Instruments this type with the provided `Span`, returning an `Instrumented` wrapper. Read more
Source§

#### fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current `Span`, returning an `Instrumented` wrapper. Read more
Source§

### impl<T, U> Into<U> for T
where U: From<T>,

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.

Source§

### impl<T> IntoEither for T

Source§

#### fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts `self` into a `Left` variant of `Either<Self, Self>` if `into_left` is `true`. Converts `self` into a `Right` variant of `Either<Self, Self>` otherwise. Read more
Source§

#### fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

Converts `self` into a `Left` variant of `Either<Self, Self>` if `into_left(&self)` returns `true`. Converts `self` into a `Right` variant of `Either<Self, Self>` otherwise. Read more
Source§

### impl<T> Pointable for T

Source§

#### const ALIGN: usize

The alignment of pointer.
Source§

#### type Init = T

The type for initializers.
Source§

#### unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
Source§

#### unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
Source§

#### unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
Source§

#### unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
Source§

### impl<T> Same for T

Source§

#### type Output = T

Should always be `Self`
Source§

### impl<T> ToOwned for T
where T: Clone,

Source§

#### type Owned = T

The resulting type after obtaining ownership.
Source§

#### fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
Source§

#### fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
Source§

### impl<T, U> TryFrom<U> for T
where U: Into<T>,

Source§

#### type Error = Infallible

The type returned in the event of a conversion error.
Source§

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

Performs the conversion.
Source§

### impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

Source§

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

The type returned in the event of a conversion error.
Source§

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

Performs the conversion.
Source§

### impl<V, T> VZip<V> for T
where V: MultiLane<T>,

Source§

#### fn vzip(self) -> V

Source§

### impl<T> WithSubscriber for T

Source§

#### 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
Source§

#### fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default `Subscriber` to this type, returning a `WithDispatch` wrapper. Read more
Source§

### impl<T> ErasedDestructor for T
where T: 'static,

## 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: 40 bytes

Size for each variant:

- `Parsed`: 40 bytes
- `Unparsed`: 16 bytes