结构初始化以满足没有显式方法定义的接口

Given pseudo go code below:

type(
    MyStruct struct {
        AFunction  func(string) ([]byte, error)
    }

    MyInterface interface {
        AFunction(string) ([]byte, error)
    }
)

func NeedThis(s string) ([]byte, error){
    //relevant function stuff
}

m := &MyStruct{AFunction: NeedThis}

The problem arises that m does not satisfy the MyInterface interface; and I can somewhat see why this would be so. Is there a way to attach functions to a struct in such a way that the constructed struct satisfies an interface without actually building out defining methods on the struct? I'm having some shadowy/faulty reasoning around this, maybe help to clarify this for me or show a better way to reason through this situation.

Could you not just define a method AFunction on MyStruct that dispatches to the stored AFunction function pointer? It's not ideal if you have a lot of these, but I think it does the job?

i.e. something like

func (s MyStruct) AFunction(str string) ([]byte, error) {
    return s.AFunction(str)
}

edit: the above may cause the compiler to error because s.AFunction is ambiguous, so you might have to give them (the method and the function pointer) different names, but it should give the right idea.

You can wrap it in another struct that implements the interface:

http://play.golang.org/p/AgnYAWBdUp

package main

import "fmt"

type (
    MyStruct struct {
        AFunction func(string) ([]byte, error)
    }

    MyInterface interface {
        AFunction(string) ([]byte, error)
    }
)

func NeedThis(s string) ([]byte, error) {
    //relevant function stuff
    return nil, nil
}

type Proxy struct {
    *MyStruct
}

func (x *Proxy) AFunction(s string) ([]byte, error) {
    return x.MyStruct.AFunction(s)
}

func main() {

    m := &MyStruct{AFunction: NeedThis}
    p := &Proxy{m}
    _, ok := MyInterface(p).(MyInterface)
    fmt.Println(ok)
}