Demonstrate that the SetYAML method only works with pointer Fields

pointer_only.go

package main

import (
	"fmt"
	"gopkg.in/yaml.v1"
	"time"
)

type timeUnMarsh struct {
	time.Time
}

func (o *timeUnMarsh) SetYAML(tag string, value interface{}) (ok bool) {
	if t, ok := value.(string); ok {
		tx, err := time.Parse(time.RFC3339Nano, t)
		if err != nil {
			return true
		}
		o.Time = tx
	}
	return true
}

type WithPointer struct {
	St *timeUnMarsh
}

type NoPointer struct {
	St timeUnMarsh
}

// for debugging, just handle errors
func errorc(err error) {
	if err != nil {
		panic(err)
	}
}

// demonstrate that SetYAML only works with Pointer fields
func main() {
	in := []byte(`st: 2009-11-10T23:00:00Z`)
	withPointer := &WithPointer{}
	err := yaml.Unmarshal(in, withPointer)
	errorc(err)
	fmt.Println("withPointer:", withPointer)

	in2 := []byte(`st: 2010-11-10T23:00:00Z`)
	noPointer := &NoPointer{}
	err = yaml.Unmarshal(in2, noPointer)
	errorc(err)
	fmt.Println("noPointer:", noPointer)

	//Output: withPointer: &{2009-11-10 23:00:00 +0000 UTC}
	//noPointer: &{0001-01-01 00:00:00 +0000 UTC}
}