强制Go类型实现接口

Question

In Go, you don’t state that you need to implement an interface, you just do it (it’s called ‘structural typing’ similar to ‘duck typing’ in dynamic languages). What if you want to force a type to implement an interface (like when you ‘inherit’ an interface in C# or Java for instance)? In other words, what if forgetting to implement an interface (or getting the signature wrong) is a mistake and you want to catch that mistake early. What is the best way to do it?

Answer 1

Best thing you may do is try to assign an instance of the type to a interface variable

For example you want to make sure type A implements Stringer interface.

You may do like this

var _ Stringer = new(A) //or
var _ Stringer = A{}

Here is the sample program, In the example A implements the interface and B does not

package main

import (
    "fmt"
)

type Stringer interface {
   String() string
}

type A struct {
}

func (a A) String() string {
    return "A"
}

type B struct {}


var _ Stringer = new(A)
var _ Stringer = new(B)

func main() {

    fmt.Println("Hello, playground")
}

Play link here : play.golang