Macro derive_redacted_debug 

macro_rules! derive_redacted_debug {
    {$t:ty} => { ... };
}

Implement std::fmt::Debug for a type that implements DebugRedacted.

The implementation will use fmt_redacted() when safe-logging is enabled, and fmt_unredacted() otherwise.

(NOTE we can’t just write ’impl<T:DebugRedacted> Debug for T`; Rust doesn’t like it.)