defmt::{panic, assert, assert_eq}

[jonas-schievink]

It would be great if defmt could be used as an efficient replacement for panic!, assert!, and assert_eq!.

These could work like this: If the panic should happen, a defmt::error! is logged with the formatting arguments, and then a core::panic!(); is raised. We might need to think about the panic payload, since a bare core::panic!() is the same as core::panic!("explicit panic");, which pulls in (or might pull in) core::fmt.

Also note that we can't use stringify! to turn the assert expression into text, since the text has to go into the symbol name. That means that assert!-style macros all have to be procedural macros and stringify part of their arguments by themselves.

This won't get rid of all inefficient panics. For example, indexing something out of bounds still uses core::fmt to format the panic string (and of course all dependencies that don't use defmt will also do that). But it should still help.