pointers - 如何访问结构字段，它是结构内部的指针，结构本身就是一个指针

Question

在我下面的代码中，为什么 *bikeSlice[0].Type 返回给我的是 Type 字段的值而不是内存地址？为什么 *bikeSlice[0] 返回 {Type:0xc0000641c0} 虽然 *bikeSlice[0].Type 似乎自动取消引用 类型字段？

package main

import "fmt"

type Bike struct {
    Type *string
}

func main() {
    type1 := "road"

    bike1 := Bike{
        Type: &type1,
    }

    type2 := "mountain"

    bike2 := Bike{
        Type: &type2,
    }

    var bikeSlice []*Bike

    bikeSlice = append(bikeSlice, &bike1)
    bikeSlice = append(bikeSlice, &bike2)

    fmt.Printf("%+v\n", *bikeSlice[0])
    fmt.Printf("%+v", *bikeSlice[0].Type)
}

Playground :https://play.golang.org/p/2Q4Bt60SUdW

输出:

{Type:0x40e128}
road

Answer 1

是的，我认为它会自动取消引用。参见 https://golang.org/ref/spec#Selectors

我认为第 3 条规则就是您正在寻找的规则:

As an exception, if the type of x is a defined pointer type and (*x).f is a valid selector expression denoting a field (but not a method), x.f is shorthand for (*x).f.