All nils are not equal in go

It’s interesting that this go code panics.

package main

import (
	"fmt"
)

type I interface {
    Name() string
}

type X struct {
    name string
}

func (x *X) Name() string {
    return x.name
}

func x() *X {
    return nil
}

func main() {
    var i I = x()
    if i != nil {
        fmt.Printf(i.Name())
    }
}

This is because nil returned from x has a type, and it’s not nil. See Why is my nil error value not equal to nil? for details.