Specific pain points for me were: - the lack of traits for numeric primitives/types without pulling in the num crate - the difficulty working with floating point types - the inconsistent type annotations in fn signatures - the type annotations are a bit clunky no easy way to alias - and auto deref mechanics especially via match statement - having to fully specify a type in a match statement or use Self::Type - the use mechanism makes no sense - no optional/default arguments without macros leads to a lot of shimming/boilerplate - having to split operations because the borrow checker can't do partials or non lexical lifetimes - the clunky range syntax wich makes writing invertible/reversible functions really ugly and error prone due to lack of inclusive range and I really can't believe the committee decided to go ahead with ..= instead of ... It's really out of line compared to pretty much every other language is doing - doesn't seem like there's a good way to nicely format long lines

Overall I still really like the language but I really don't see it taking off until these issues are fixed because it makes it so hard to start up.