Remove Debug bound for Resource trait.

[Object905]

When using type from other crate not every type implements Debug, and Debug is not use everywhere meaningfully anyway.

[torkleyy]

I added the trait bound intentionally. According to the API guidelines, every type should implement Debug. Without forcing the bound, we cannot debug Resources.

[torkleyy]

cc @kvark @Aceeri

[kvark]

Why don't we lift the restriction from Resource but still have derive(Debug) working only when Resource: Debug?

[torkleyy]

That's not possible; there is no way to find out if all the types are Debug (nor access their vtables) because we have trait objects in Resources.

[kvark]

To be honest, I find this requirement (to have everything public as Debug) to be a little ridiculous. Is there a debugging use case where Resource: Debug would really help?

[torkleyy]

To be honest, I find this requirement (to have everything public as Debug) to be a little ridiculous.

It is.

Is there a debugging use case where Resource: Debug would really help?

Well, just if you want to print all components...which brings me to the idea that we could use @Aceeri's component groups for this. I guess that's a great compromise. Thanks everybody!