Possible to add another drain to an existing root logger?

[smahm006]

Apologies if this is a basic question but I did not find something in the docs for this.

Let's say you built the root logger in the beginning of your program and then you needed to add a new file drain to the root logger if a certain condition is met in the middle of your program, would that be doable?

[dpc]

You can either use the existing Logger as a Drain for a new Logger that will replace the old one (because of https://docs.rs/slog/latest/slog/trait.Drain.html#impl-Drain-2), or you can implement your own struct MyMagicDrain that impl Drain for MyMagicDrain and inside do some magic to conditionally log to different places. There's also https://docs.rs/slog-atomic/