package main

import (
	"fmt"
)


type S1 struct {i int; j int}

func typeName(v interface{}) string {
	switch v.(type) {
	case int:
		return "int"
	case string:
		return "string" 
    case *S1:
        return "S1"
	default:
		return "unknown"
	}
}


func typeName2(v interface{}) string {
    kk := 2
	switch i := v.(type) {
	case int:
        assert(i + kk == 890)
		return "int"
	case string:
		return "string" 
    case *S1:
		_ = i
        return "S1"
	case []int:
		return "[]int"
	case map[string]int:
		return "map[string]int"
	case map[string][]int:
		return "map[string][]int"	
	default:
		return "unknown"
	}
	return "int"
}

func main() {
   var s *S1;
   re := typeName(s)
   assert(re == "S1")
   re = typeName2(888)
   re2 := typeName2([]int{1})
   re3 := typeName2(map[string]int{"a":1})
   re4 := typeName2(map[string][]int{"a":{1}})
   fmt.Println("typeswitch", re, re2, re3, re4)
   assert(re == "int")
   

}