future-mod.go

package main

import (
	"fmt"
	"time"
)

type Future struct {
	C chan struct{}
}

func NewFuture() *Future {
	return &Future{ make(chan struct{}) }
}

func (f *Future) Wait() {
	<- f.C
}
func (f *Future) Resolve() {
	f.C <- struct{}{}
}
func main() {
	var value string
	f := NewFuture()
	
	go func() {
		time.Sleep(10 * time.Second)
		fmt.Println("10 seconds later")
		value = "hello world"
		f.Resolve()
	}()
	
	f.Wait()
	fmt.Println(value)
}