Nothing is perfect, but a well defined and discoverable set of features, built into the language and checked for validity is great. Also having it be a feature

Nothing is perfect, but a well defined and discoverable set of features, built into the language and checked for validity is great. Also having it be a feature system and not shoved into one big pre-processor soup (I.e the same thing as build time constants) is also good. Having them support groups and compose together is even better. There are other languages that improve on c/c++, but rust is just top of my mind right now.