pub type Callback<T> = Box<dyn Fn(&dyn AsyncInstrument<T>) + Send + Sync>;Expand description
A function registered with a Meter that makes observations for the instruments it is registered with.
The async instrument parameter is used to record measurement observations for these instruments.
The function needs to complete in a finite amount of time.
§Panics
Callbacks should avoid panicking. The SDK does not currently isolate or recover from panics occurring within observable callbacks. If an operation inside a callback can panic, the caller should catch the panic or handle the error within the callback.
Aliased Type§
pub struct Callback<T>(/* private fields */);