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pub struct ExtensionsMut<'a> { /* private fields */ }
Expand description

An mutable reference to a Span’s extensions.

Implementations

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.

Replaces an existing T into this extensions.

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

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

Remove a type from this Extensions.

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

Trait Implementations

Formats the value using the given formatter. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more