Go lang empty struct confusing feature [duplicate]

问题

This question already has answers here:

why struct arrays comparing has different result (1 answer)

Addresses of slices of empty structs (2 answers)

Closed 14 days ago.

Here is my code:

package main

import (
    "fmt"
)

type A struct{}

func main() {
    var ad, bd A
    res1 := &ad == &bd
    res2 := ad == bd
    fmt.Println(res1, res2)// true true
    fmt.Printf("%p, %p\n", &ad, &bd) // 0x57bb60, 0x57bb60
}

Now if I comment the last line of main function like this:

package main

import (
    "fmt"
)

type A struct{}

func main() {
    var ad, bd A
    res1 := &ad == &bd
    res2 := ad == bd
    fmt.Println(res1, res2) // false true
    //fmt.Printf("%p, %p\n", &ad, &bd)
}

The program prints false true!

How can the last line influence the output? Is there any special feature with the empty struct? Or this problem is caused by the compiler?

来源：https://stackoverflow.com/questions/62155916/go-lang-empty-struct-confusing-feature