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

func silly() (interface{}, error) {
    return "silly", nil
}

v, err := silly()
if err != nil {
    // handle error
}

s, ok := v.(string)
if !ok {
    // the assertion failed.
}

but more likely what you actually want is to use a type switch, like-a-this:

switch t := v.(type) {
case string:
    // t is a string
case int :
    // t is an int
default:
    // t is some other type that we didn't name.
}

Go is really more about correctness than it is about terseness.