Analogue for C++ Enum in Golang

I rewrite some C++ code, but could not find an elegant solution. For example:

#include <iostream>

enum color
std::ostream& operator<<(std::ostream& os, color c)
        case red   : os << "red";    break;
        case yellow: os << "yellow"; break;
        case green : os << "green";  break;
        case blue  : os << "blue";   break;
        default    : os.setstate(std::ios_base::failbit);
    return os;
int main()
    color col = red;
    std::cout << "col = " << col <<std::endl;

What corresponds to Go enum from C++?

you can use iota.

package main

const (
        a = iota 
        b = iota
        c = iota

func main () {
	println (a, b, c)

That would be Iota.

as far as I understood iota allows create a number of constant variables with a sequence value. But enum in C++ has another purpose: to create an object from a bounded domain values. this is the aspect that interests me. I’m sorry that is not clearly formulated idea originally.

Turn out you can make iota work like this.

(edit: copy-paste code in link, in case it does not work)

package main

import "fmt"

type Color int

const (
    red Color = iota

func (c *Color) Name() string {
    switch *c {
    case red:
        return "red"
    case yellow:
        return "yellow"
    case green:
        return "green"
    case blue:
        return "blue"
    return ""

func main() {
    col := red
    fmt.Println("col = ", col.Name())

Thank you, what was needed. I forgot that in Go alias type is a new type.

You can also use the go:generate with the stringer command, like this article from the go blog. Then you don’t even need to write the function!

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