go - Explanation of checking if value implements interface

Question

I've read "Effective Go" and other Q&As like this: golang interface compliance compile type check , but nonetheless I can't understand properly how to use this technique.

Please, see example:

type Somether interface {
    Method() bool
}

type MyType string

func (mt MyType) Method2() bool {
    return true
}

func main() {
    val := MyType("hello")

    //here I want to get bool if my value implements Somether
    _, ok := val.(Somether)
    //but val must be interface, hm..what if I want explicit type?

    //yes, here is another method:
    var _ Iface = (*MyType)(nil)
    //but it throws compile error
    //it would be great if someone explain the notation above, looks weird
}

Is there any simple ways (eg without using reflection) check value if it implements an interface?

Answer 1

Waitting for answers