Generics type conversion example

generics.go

package main

import (
	"fmt"
)

type User struct {
	FullName string
	Removed  bool
}

type Account struct {
	Name    string
	Removed bool
}

type Scanner[T User | Account] interface {
	Scan()
	*T
}

type Model interface {
	User | Account
}

func (user *User) Scan() {
	user.FullName = `changed in scan method`
	user.Removed = true
}

func (account *Account) Scan() {
	account.Name = `changed in scan method`
	account.Removed = true
}

func setRemovedState[T Model, PT Scanner[T]](state bool) *T {
	var obj T

	pointer := PT(&obj)
	pointer.Scan() // calling method on non-nil pointer

	return &obj
}

func main() {
	user := setRemovedState[User](true)
	account := setRemovedState[Account](true)

	fmt.Printf("User: %v\n", *user)
	fmt.Printf("Account: %v\n", *account)
}