> Tracing value types through a function is a solved problem. Sure, i think that(type inference/flow typing) is solved in kotlin too. Sorry, i don't get the is

> Tracing value types through a function is a solved problem. Sure, i think that(type inference/flow typing) is solved in kotlin too. Sorry, i don't get the issue here. The last return value is throwing a compile time error because it breaks the function contract, which expects a non null value.