[][src]Struct tracing_subscriber::registry::ExtensionsMut

pub struct ExtensionsMut<'a> { /* fields omitted */ }

An mutable reference to a Span's extensions.


impl<'a> ExtensionsMut<'a>[src]

pub fn insert<T: Send + Sync + 'static>(&mut self, val: T)[src]

Insert a type into this Extensions.

Note that extensions are not Layer-specific—they are span-specific. This means that other layers can access and mutate extensions that a different Layer recorded. For example, an application might have a layer that records execution timings, alongside a layer that reports spans and events to a distributed tracing system that requires timestamps for spans. Ideally, if one layer records a timestamp x, the other layer should be able to reuse timestamp x.

Therefore, extensions should generally be newtypes, rather than common types like String, to avoid accidental cross-Layer clobbering.


If T is already present in Extensions, then this method will panic.

pub fn replace<T: Send + Sync + 'static>(&mut self, val: T) -> Option<T>[src]

Replaces an existing T into this extensions.

If T is not present, Option::None will be returned.

pub fn get_mut<T: 'static>(&mut self) -> Option<&mut T>[src]

Get a mutable reference to a type previously inserted on this ExtensionsMut.

pub fn remove<T: Send + Sync + 'static>(&mut self) -> Option<T>[src]

Remove a type from this Extensions.

If a extension of this type existed, it will be returned.

Trait Implementations

impl<'a> Debug for ExtensionsMut<'a>[src]

Auto Trait Implementations

impl<'a> !RefUnwindSafe for ExtensionsMut<'a>

impl<'a> !Send for ExtensionsMut<'a>

impl<'a> Sync for ExtensionsMut<'a>

impl<'a> Unpin for ExtensionsMut<'a>

impl<'a> !UnwindSafe for ExtensionsMut<'a>

Blanket Implementations

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

impl<T> Borrow<T> for T where
    T: ?Sized

impl<T> BorrowMut<T> for T where
    T: ?Sized

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

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

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 

type Error = Infallible

The type returned in the event of a conversion error.

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

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

The type returned in the event of a conversion error.