Generic Box

A generic struct stores a value whose type is supplied when the struct is used.

generic_box.go

package main

import "fmt"

// Generic shape: Box[T any] struct { Value T }
type IntBox struct {
	Value int
}

func (box IntBox) String() string {
	return fmt.Sprint(box.Value)
}

func main() {
	var size = 
	box := IntBox{Value: size}
	text := box.String()

	fmt.Println("size=", size)
	fmt.Println("text=", text)
	fmt.Println("double=", box.Value*2)
}

package main

import "fmt"

// Generic shape: Box[T any] struct { Value T }
type IntBox struct {
	Value int
}

func (box IntBox) String() string {
	return fmt.Sprint(box.Value)
}

func main() {
	var size = 
	box := IntBox{Value: size}
	text := box.String()

	fmt.Println("size=", size)
	fmt.Println("text=", text)
	fmt.Println("double=", box.Value*2)
}

package main

import "fmt"

// Generic shape: Box[T any] struct { Value T }
type IntBox struct {
	Value int
}

func (box IntBox) String() string {
	return fmt.Sprint(box.Value)
}

func main() {
	var size = 
	box := IntBox{Value: size}
	text := box.String()

	fmt.Println("size=", size)
	fmt.Println("text=", text)
	fmt.Println("double=", box.Value*2)
}

generic struct A generic struct can keep the same fields and methods while changing the stored value type. The trace uses a concrete integer box and shows the generic shape in a comment.