# [−] [src] Enum proc_macro2::TokenTree

    pub enum TokenTree {
        Group(Group),
        Ident(Ident),
        Punct(Punct),
        Literal(Literal),
    }

A single token or a delimited sequence of token trees (e.g. `[1, (), ..]`).

## Variants

`Group(Group)`

A token stream surrounded by bracket delimiters.

`Ident(Ident)`

An identifier.

`Punct(Punct)`

A single punctuation character (`+`, `,`, `$`, etc.).

`Literal(Literal)`

A literal character (`'a'`), string (`"hello"`), number (`2.3`), etc.

## Implementations

### `impl TokenTree` [src]

#### `pub fn span(&self) -> Span` [src]

Returns the span of this tree, delegating to the `span` method of the contained token or a delimited stream.

#### `pub fn set_span(&mut self, span: Span)` [src]

Configures the span for only this token.

Note that if this token is a `Group` then this method will not configure the span of each of the internal tokens, this will simply delegate to the `set_span` method of each variant.

## Trait Implementations

### `impl Clone for TokenTree` [src]

#### `fn clone(&self) -> TokenTree` [src]

Returns a copy of the value. Read more

#### `fn clone_from(&mut self, source: &Self)`1.0.0 [src]

Performs copy-assignment from `source`. Read more

### `impl Debug for TokenTree` [src]

Prints token tree in a form convenient for debugging.

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

Formats the value using the given formatter. Read more

### `impl Display for TokenTree` [src]

Prints the token tree as a string that is supposed to be losslessly convertible back into the same token tree (modulo spans), except for possibly `TokenTree::Group`s with `Delimiter::None` delimiters and negative numeric literals.

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

Formats the value using the given formatter. Read more

### `impl Extend<TokenTree> for TokenStream` [src]

#### `fn extend<I: IntoIterator<Item = TokenTree>>(&mut self, streams: I)` [src]

Extends a collection with the contents of an iterator. Read more

#### `fn extend_one(&mut self, item: A)` [src]

🔬 This is a nightly-only experimental API. (`extend_one`)

Extends a collection with exactly one element.

#### `fn extend_reserve(&mut self, additional: usize)` [src]

🔬 This is a nightly-only experimental API. (`extend_one`)

Reserves capacity in a collection for the given number of additional elements. Read more

### `impl From<Group> for TokenTree` [src]

#### `fn from(g: Group) -> TokenTree` [src]

Performs the conversion.

### `impl From<Ident> for TokenTree` [src]

#### `fn from(g: Ident) -> TokenTree` [src]

Performs the conversion.

### `impl From<Literal> for TokenTree` [src]

#### `fn from(g: Literal) -> TokenTree` [src]

Performs the conversion.

### `impl From<Punct> for TokenTree` [src]

#### `fn from(g: Punct) -> TokenTree` [src]

Performs the conversion.

### `impl From<TokenTree> for TokenStream` [src]

#### `fn from(token: TokenTree) -> Self` [src]

Performs the conversion.

### `impl FromIterator<TokenTree> for TokenStream` [src]

Collects a number of token trees into a single stream.

#### `fn from_iter<I: IntoIterator<Item = TokenTree>>(streams: I) -> Self` [src]

Creates a value from an iterator. Read more

## Auto Trait Implementations

### `impl RefUnwindSafe for TokenTree`

### `impl !Send for TokenTree`

### `impl !Sync for TokenTree`

### `impl Unpin for TokenTree`

### `impl UnwindSafe for TokenTree`

## Blanket Implementations

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `pub fn type_id(&self) -> TypeId` [src]

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

### `impl<T> Borrow<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow(&self) -> &T` [src]

Immutably borrows from an owned value. Read more

### `impl<T> BorrowMut<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow_mut(&mut self) -> &mut T` [src]

Mutably borrows from an owned value. Read more

### `impl<T> From<T> for T` [src]

#### `pub fn from(t: T) -> T` [src]

Performs the conversion.

### `impl<T, U> Into<U> for T where
U: From<T>,` [src]

#### `pub fn into(self) -> U` [src]

Performs the conversion.

### `impl<T> ToOwned for T where
T: Clone,` [src]

#### `type Owned = T`

The resulting type after obtaining ownership.

#### `pub fn to_owned(&self) -> T` [src]

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

#### `pub fn clone_into(&self, target: &mut T)` [src]

🔬 This is a nightly-only experimental API. (`toowned_clone_into`)

recently added

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

### `impl<T> ToString for T where
T: Display + ?Sized,` [src]

#### `pub default fn to_string(&self) -> String` [src]

Converts the given value to a `String`. Read more

### `impl<T, U> TryFrom<U> for T where
U: Into<T>,` [src]

#### `type Error = Infallible`

The type returned in the event of a conversion error.

#### `pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>` [src]

Performs the conversion.

### `impl<T, U> TryInto<U> for T where
U: TryFrom<T>,` [src]

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

The type returned in the event of a conversion error.

#### `pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>` [src]

Performs the conversion.