proposal: Support for a feature in Generics like Typescript has <T extends {name: string}>

[Ammce]

Hi there,

I have been trying out the Golang Generics, and I love them. Great work! However, one thing that I am using a lot in Typescript seems to be missing, or I can not find an answer anywhere. I would love to be able to create a function that accepts a generic struct element with a minimum requirement of a property that needs to be passed to the function. Something like that exists in a Typescript where <T extends {name: string}>

Let's analyze the code below. In the function printNameAndAge, on the place where I put (*extends*) placeholder, I think it would be awesome if somehow we could specify that it is a minimum property of a struct requirement for this function as I will work only with Age and Name

Note: I have seen many workarounds with Interfaces for this, by implementing a function for each property, and all of that seems too messy for such a simple requirement. Once again, I might miss it, or missed the point completely about it, as I have just started exploring Generics in Go, and I am coming from Typescript world.

import "fmt"

type User struct {
	Name   string
	Age    int
	Height float32
}

type Car struct {
	Age   int
	Name  string
	Model string
}

type NameAndAge struct {
	Name string
	Age  int
}


func printNameAndAge[T (*extends*) NameAndAge](u T) {
	fmt.Println(u.Name)
	fmt.Println(u.Age)
}

func main() {
	newUser := User{
		Name:   "John",
		Age:    24,
		Height: 186,
	}
	newCar := Car{
		Name:  "Series 3",
		Age:   1,
		Model: "BMW",
	}

	printNameAndAge(newUser)
	printNameAndAge(newCar)

}

[DeedleFake]

Not for or against, but I think that a more Go-like syntax would be to make it part of the type set system. For example,

type NameAndAge interface {
  ~struct {
    Name ~string // Being able to use ~ on the fields might be overkill...
    Age ~int
    ... // Literal ... in the code to indicate that more fields are allowed. Possibly unnecessary.
  }
}

[seankhliao]

Duplicate of #51259