Programming

In Rust you’re kind of stuck with it, but at the end of the day combined return types are just syntactic sugar for something a lot of languages can do. Even in plain old C there’s a pattern where you pass pointers to your return and/or error variables. In many languages you can return structs or similar. In some I’d argue it looks nicer than having to write Result<>, e.g. in Python or in Swift you can just return a tuple by putting things in parentheses. (Of course you can also still use something more explicit too. But if every function returned (result, error) by default and every call was like result, error = fn(), I don’t think it’d be necessary.)

However I don’t really know of any language where people prefer to use this over exceptions if exceptions are available. Even in C some people used to use setjmp/longjmp in macros to implement exceptions. Exceptions have their problems but people seem to overwhelmingly be in favor of them.

Personally I like exceptions in languages that have some kind of built-in “finally” for functions. For example defer in Swift. You can have proper error handling for a lot less typing in many cases because passing through exceptions is fine if your defer blocks handle the cleanup. And if you do want to handle an exception, Swift also has optionals, and a try? that transparently converts a return value into an optional that’s nil when an exception was thrown, and a coalescing operator ??, which means you can catch exceptions and provide a default value on one line, instead of a 4-5 line try..catch/except block or an error checking conditional for every call.