Enum `Delimiter`

pub enum Delimiter

Describes how a sequence of token trees is delimited.

Variants

Parenthesis

( ... )

Brace

{ ... }

Bracket

[ ... ]

None

∅ ... ∅

An invisible delimiter, that may, for example, appear around tokens coming from a "macro variable" $var. It is important to preserve operator priorities in cases like $var * 3 where $var is 1 + 2. Invisible delimiters may not survive roundtrip of a token stream through a string.

Note: rustc currently can ignore the grouping of tokens delimited by None in the output of a proc_macro. Only None-delimited groups created by a macro_rules macro in the input of a proc_macro macro are preserved, and only in very specific circumstances. Any None-delimited groups (re)created by a proc_macro will therefore not preserve operator priorities as indicated above. The other Delimiter variants should be used instead in this context. This is a rustc bug. For details, see rust-lang/rust#67062.

Trait Implementations

`impl Clone for Delimiter`

fn clone(&self) -> Delimiter

`impl Copy for Delimiter`

`impl Debug for Delimiter`

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

`impl Eq for Delimiter`

`impl PartialEq for Delimiter`

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

`impl StructuralPartialEq for Delimiter`

Auto Trait Implementations

`impl Freeze for Delimiter`

`impl RefUnwindSafe for Delimiter`

`impl Send for Delimiter`

`impl Sync for Delimiter`

`impl Unpin for Delimiter`

`impl UnsafeUnpin for Delimiter`

`impl UnwindSafe for Delimiter`

Blanket Implementations

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

fn type_id(&self) -> TypeId

`impl<T> Borrow<T> for Delimiter where T: ?Sized,`

fn borrow(&self) -> &T

`impl<T> BorrowMut<T> for Delimiter where T: ?Sized,`

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

`impl<T> CloneToUninit for Delimiter where T: Clone,`

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

`impl<T> From<T> for Delimiter`

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

`impl<T> ToOwned for Delimiter where T: Clone,`

type Owned = T;
fn to_owned(&self) -> T
fn clone_into(&self, target: &mut T)

`impl<T, U> Into<U> for Delimiter where U: From<T>,`

fn into(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<U> for Delimiter where U: Into<T>,`

type Error = never;
fn try_from(value: U) -> Result<T, never>

`impl<T, U> TryInto<U> for Delimiter where U: TryFrom<T>,`

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