如何在Go中声明接口数组

I am having difficulty in what should be a trivial task of creating an interface array. Here is my code,

var result float64
for i := 0; i < len(diff); i++ {
    result += diff[i]
}
result = 1 / (1 + math.Sqrt(result))

id1 := user1.UserId
id2 := user2.UserId

user1.Similar[id2] = [2]interface{id2, result}
user2.Similar[id1] = [2]interface{id1, result}

result is a float and user*.UserId is an int.

My error message is

syntax error: name list not allowed in interface type

For example,

package main

import (
    "fmt"
)

func main() {
    x, y := 1, "@"
    a := [2]interface{}{x, y}
    fmt.Println(a)
    b := [2]interface{}{0, "x"}
    fmt.Println(b)
}

Output:

[1 @]
[0 x]