# [−] [src] Struct proc_macro2::Span

    pub struct Span { /* fields omitted */ }

A region of source code, along with macro expansion information.

## Implementations

### `impl Span` [src]

#### `pub fn call_site() -> Span` [src]

The span of the invocation of the current procedural macro.

Identifiers created with this span will be resolved as if they were written directly at the macro call location (call-site hygiene) and other code at the macro call site will be able to refer to them as well.

#### `pub fn mixed_site() -> Span` [src]

The span located at the invocation of the procedural macro, but with local variables, labels, and `$crate` resolved at the definition site of the macro. This is the same hygiene behavior as `macro_rules`.

This function requires Rust 1.45 or later.

#### `pub fn resolved_at(&self, other: Span) -> Span` [src]

Creates a new span with the same line/column information as `self` but that resolves symbols as though it were at `other`.

#### `pub fn located_at(&self, other: Span) -> Span` [src]

Creates a new span with the same name resolution behavior as `self` but with the line/column information of `other`.

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

Convert `proc_macro2::Span` to `proc_macro::Span`.

This method is available when building with a nightly compiler, or when building with rustc 1.29+ without semver exempt features.

# Panics

Panics if called from outside of a procedural macro. Unlike `proc_macro2::Span`, the `proc_macro::Span` type can only exist within the context of a procedural macro invocation.

#### `pub fn join(&self, other: Span) -> Option<Span>` [src]

Create a new span encompassing `self` and `other`.

Returns `None` if `self` and `other` are from different files.

Warning: the underlying `proc_macro::Span::join` method is nightly-only. When called from within a procedural macro not using a nightly compiler, this method will always return `None`.

## Trait Implementations

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

#### `fn clone(&self) -> Span` [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 Copy for Span` [src]

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

Prints a span in a form convenient for debugging.

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

Formats the value using the given formatter. Read more

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

#### `fn from(proc_span: Span) -> Span` [src]

Performs the conversion.

## Auto Trait Implementations

### `impl RefUnwindSafe for Span`

### `impl !Send for Span`

### `impl !Sync for Span`

### `impl Unpin for Span`

### `impl UnwindSafe for Span`

## 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, 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.