Collects and records trace data.
A guard that resets the current default dispatcher to the prior default dispatcher when dropped.
Returned if setting the global dispatcher fails.
Trait representing the functions required to collect trace data.
Sets the subscriber as the default for the duration of the lifetime of the
Sets this subscriber as the global default for the duration of the entire program.
Will be used as a fallback if no thread-local subscriber has been set in a thread (using
Sets this subscriber as the default for the duration of a closure.