Any difference in using an empty interface or an empty struct as a map's value?

Question

I am using this construct to simulate a set

type MyType uint8 map[MyType]interface{} 

I then add in all my keys and map them to nil.

I've learnt that it is also possible to use

map[MyType]struct{} 

Any benefits of using the empty struct versus interface{}.

Answer 1

Memory usage. For example, types struct{}, interface{}, and bool,

package main  import (     "fmt"     "unsafe" )  func main() {     var s struct{}     fmt.Println(unsafe.Sizeof(s))     var i interface{}     fmt.Println(unsafe.Sizeof(i))     var b bool     fmt.Println(unsafe.Sizeof(b)) } 

Output (bytes for 32-bit architecture):

0 8 1 

Output (bytes for 64-bit architecture):

0 16 1 

References:

Go Data Structures: Interfaces