Enum `Meta`

enum Meta

Content of a compile-time structured attribute.

Path

A meta path is like the test in #[test].

List

A meta list is like the derive(Copy) in #[derive(Copy)].

NameValue

A name-value meta is like the path = "..." in #[path = "sys/windows.rs"].

Syntax tree enum

This type is a syntax tree enum.

Variants

Path(crate::path::Path)
List(MetaList): A structured list within an attribute, like derive(Copy, Clone).
NameValue(MetaNameValue): A name-value pair within an attribute, like feature = "nightly".

Implementations

`impl Meta`

fn path(self: &Self) -> &Path

Returns the path that begins this structured meta item.

For example this would return the test in #[test], the derive in #[derive(Copy)], and the path in #[path = "sys/windows.rs"].

fn require_path_only(self: &Self) -> Result<&Path>

Error if this is a Meta::List or Meta::NameValue.

fn require_list(self: &Self) -> Result<&MetaList>

Error if this is a Meta::Path or Meta::NameValue.

fn require_name_value(self: &Self) -> Result<&MetaNameValue>

Error if this is a Meta::Path or Meta::List.

`impl Clone for Meta`

fn clone(self: &Self) -> Self

`impl Debug for Meta`

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

`impl Eq for Meta`

`impl Freeze for Meta`

`impl From for Meta`

fn from(meta: Path) -> Meta

`impl From for Meta`

fn from(meta: MetaNameValue) -> Meta

`impl From for Meta`

fn from(meta: MetaList) -> Meta

`impl Hash for Meta`

fn hash<H>(self: &Self, state: &mut H) where H: Hasher

`impl Parse for Meta`

fn parse(input: ParseStream<'_>) -> Result<Self>

`impl PartialEq for Meta`

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

`impl RefUnwindSafe for Meta`

`impl Send for Meta`

`impl Sync for Meta`

`impl ToTokens for Meta`

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

`impl Unpin for Meta`

`impl UnsafeUnpin for Meta`

`impl UnwindSafe for Meta`

`impl<T> Any for Meta`

fn type_id(self: &Self) -> TypeId

`impl<T> Borrow for Meta`

fn borrow(self: &Self) -> &T

`impl<T> BorrowMut for Meta`

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

`impl<T> CloneToUninit for Meta`

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

`impl<T> From for Meta`

fn from(t: T) -> T: Returns the argument unchanged.

`impl<T> Spanned for Meta`

fn span(self: &Self) -> Span

`impl<T> ToOwned for Meta`

fn to_owned(self: &Self) -> T
fn clone_into(self: &Self, target: &mut T)

`impl<T, U> Into for Meta`

fn into(self: Self) -> U

Calls U::from(self).

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

`impl<T, U> TryFrom for Meta`

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

`impl<T, U> TryInto for Meta`

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