根据 struct 的 一个 filed 获取 struct 的指针！

gistfile1.txt

import (
    "fmt"
    "unsafe"
)

type A struct {
    data string
    e    int
}

func main() {
    a := &A{"abc", 1234}
    e := &(a.e)

    offset := uintptr(unsafe.Offsetof(A{}.e))
    base := uintptr(unsafe.Pointer(e)) - offset
    x := (*A)(unsafe.Pointer(base))

    fmt.Printf("%p , %p, %#v\n", a, x, x)
}