I like the idea! I disagree with other commenters here that dependency injection is not useful. I think it doesn't come across well in toy examples, but in my

I like the idea! I disagree with other commenters here that dependency injection is not useful. I think it doesn't come across well in toy examples, but in my experience it is very useful for large services, which otherwise tend to accrue a big rats nest of instantiation in the startup code, which is difficult to modularize. I haven't built a service like that in Rust yet, so maybe other patterns work well, but I have noted these big instantiation entry points in rust code that I've read, so I'm skeptical that it is a solved problem. I do agree that it introduces a significant legibility and debugging burden, but I think that can be significantly better with compile time DI. However, I think it does require good tools that would take quite awhile to be built for an immature framework like this. But the thing I'm most skeptical of here is the implementation. Is there not enough information available in a normal procedural macro to figure out the dependencies, without using this trick with the rustdoc data? That approach seems very cheesy and likely fragile to me.