My new favourite golang config pattern

config.go

package config

import "flag"

var BindAddress string
var SMTPHost string
var SMTPPort int

func Configure() {
	flag.StringVar(&BindAddress, "bind", ":9650", "Bind address")
	flag.StringVar(&SMTPHost, "smtp-host", "localhost", "SMTP server host")
	flag.IntVar(&SMTPPort, "smtp-port", 587, "SMTP server port")
	flag.Parse()
}

var _ = func() { Configure() }

Why not just rename Configure() to init() which eliminates the need for the 'var _' declaration?

Using an unbound variable declaration to invoke a function for it's side-effects is esoteric, at best.