Struct tracing_subscriber::registry::ExtensionsMut
source · [−]pub struct ExtensionsMut<'a> { /* private fields */ }
Expand description
An mutable reference to a Span’s extensions.
Implementations
sourceimpl<'a> ExtensionsMut<'a>
impl<'a> ExtensionsMut<'a>
sourcepub fn insert<T: Send + Sync + 'static>(&mut self, val: T)
pub fn insert<T: Send + Sync + 'static>(&mut self, val: T)
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.
Panics
If T
is already present in Extensions
, then this method will panic.
sourcepub fn replace<T: Send + Sync + 'static>(&mut self, val: T) -> Option<T>
pub fn replace<T: Send + Sync + 'static>(&mut self, val: T) -> Option<T>
Replaces an existing T
into this extensions.
If T
is not present, Option::None
will be returned.
Trait Implementations
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
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<T> Instrument for T
impl<T> Instrument for T
sourcefn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
sourcefn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
sourceimpl<T> WithSubscriber for T
impl<T> WithSubscriber for T
sourcefn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self> where
S: Into<Dispatch>,
fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self> where
S: Into<Dispatch>,
Attaches the provided Subscriber
to this type, returning a
WithDispatch
wrapper. Read more
sourcefn with_current_subscriber(self) -> WithDispatch<Self>
fn with_current_subscriber(self) -> WithDispatch<Self>
Attaches the current default Subscriber
to this type, returning a
WithDispatch
wrapper. Read more