I actually think I forgot how to program in C. It lacks almost every data structure I'd deem useful to getting complex and mixed problems solved quickly. C++ provides many things and is useful if you are in a tight spot or you want/need the speed.

If Rust keeps evolving at a quick pace I think I'll look into it a lot in the future.

D seems to me like a good thing that is better in many ways but has some critical drawbacks for me like not working on many microcontrollers (an area where C++ really shines). On the other hand it isn't radical enough to really dive into it.