# 1.29.0[−][src]Enum proc_macro::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.

## Methods

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

Creates a token stream containing a single token tree.

#### `fn from(tree: TokenTree) -> TokenStream`[src]

Performs the conversion.

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

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

Performs the conversion.

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

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

Performs the conversion.

### `impl Extend<TokenTree> for TokenStream`
1.30.0
[src]

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

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

### `impl !Send for TokenTree`[src]

### `impl !Sync for TokenTree`[src]

### `impl ToString for TokenTree`
1.15.0
[src]

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

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

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

Collects a number of token trees into a single stream.

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

Creates a value from an iterator. Read more

## Blanket Implementations

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

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

Performs the conversion.

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

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

Performs the conversion.

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

#### `type Owned = T`

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

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

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

🔬 This is a nightly-only experimental API. (`toowned_clone_into` #41263)

recently added

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

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

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

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

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

#### `type Error = !`

🔬 This is a nightly-only experimental API. (`try_from` #33417)

The type returned in the event of a conversion error.

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

🔬 This is a nightly-only experimental API. (`try_from` #33417)

Performs the conversion.

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

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

Immutably borrows from an owned value. Read more

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

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

Mutably borrows from an owned value. Read more

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

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

🔬 This is a nightly-only experimental API. (`try_from` #33417)

The type returned in the event of a conversion error.

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

🔬 This is a nightly-only experimental API. (`try_from` #33417)

Performs the conversion.

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

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

🔬 This is a nightly-only experimental API. (`get_type_id` #27745)

this method will likely be replaced by an associated static

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

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