Using map[...]bool to simulate a set in golang.

simulate-a-set.go

package main

import "fmt"

var validNames = map[string]bool{
  "blue":   true,
	"yellow": true,
}

func main() {
	if validNames["blue"] {
		fmt.Println("blue is ok!")
	}
	if validNames["green"] {
		fmt.Println("green is ok!")
	}
}