To be fair, the issue of ergonomics is an artifact of C only. In a language with proper sum types (or as I like to think of them, "better enums"), the pattern w

To be fair, the issue of ergonomics is an artifact of C only. In a language with proper sum types (or as I like to think of them, "better enums"), the pattern would look more like this: match library_function(arg) { Ok(num) => // success Err(errno) => // failure } But since C doesn't have proper sum types, we have to approximate this pattern with things like errno or returned structs.