The Go idiom for set is a map with bool values and given that it'll just return false for keys that aren't initialized I really don't see what you're missing co

The Go idiom for set is a map with bool values and given that it'll just return false for keys that aren't initialized I really don't see what you're missing compared to having a dedicated type. I'm not sure what your complaint is about maps, lists, or sorting. There are some specialized types you might occasionally want and I miss FP constructs too, but I don't think these are really serious impediments to productivity.