oddly, the feature that is suggested as being awesome is in fact go's _worst_ feature, which is:

value tuples are not error handling.

it is not sufficient to rely on an IDE or linter to catch lack of error-case handling. they are semantically identical, and in practise worse, to exceptions: at least exceptions will bubble up, and be caught.. somewhere.

and i'm not saying exceptions are the solution. they really are awful. in my opinion, 'either'/'oneof' types are the best solution here: if something returns either a failure of a success value, then you as a developer are forced to handle the failure condition:

    // pseudo c#
    either<error, int> result = get_string_length(str);
    return reslut.match(left: _ => 0, right: x => x);
 

you may choose to throw an exception, you may choose to return a default. but you absolutely cannnot _not_ handle this function's failure condition (sorry, double negative..).