Rust, reflection and access rules
Reflection is something a lot of people wish the Rust language had: It is not hard to stumble across somebody with an interesting use case for it. People want to use it for serialization, GCs, better interop, and so, so much more. If you can think of a task, there is somebody out there wishing they could implement it using reflection. Sadly, it does not look like it is coming any time soon. Still,
