Idiomatic way to do conversion/type assertion on multiple return values in Go

Question

What is the idiomatic way to cast multiple return values in Go?

Can you do it in a single line, or do you need to use temporary variables such as I\'ve done in my exampl

Answer 1

template.Must is the standard library's approach for returning only the first return value in one statement. Could be done similarly for your case:

func must(v interface{}, err error) interface{} {
    if err != nil {
        panic(err)
    }
    return v
}

// Usage:
str2 := must(twoRet()).(string)

By using must you basically say that there should never be an error, and if there is, then the program can't (or at least shouldn't) keep operating, and will panic instead.