Logging levels ordered from most messages printed to fewest. Or from lowest severity/priority to highest severity/priority.

If a message level is greater than or equal to the logging threshold, it will be printed.

E.g.,

• Trace messages are only printed at log level threshold of Trace.
• Info messages are printed at log level threshold of Info and below (Trace, Debug, and Info).
• Error messages are printed at log level threshold of Error and below.

If the log level is set to Silent no messages will be printed (regardless of their level).

(Trace < Debug < Info < Warning < Error < Fatal < Unknown < Silent)

of_string level attempts to create a t from its case-insensitive string representation (e.g., for creating from command line arguments).

to_string t converts the t to its string representation (e.g., for printing).