Implement the Stack and Queue class through "container/list" package. golang version: 1.2

Stack.go

package main

import (
	"container/list"
	"fmt"
	"sync"
)

// Define Stack class
type Stack struct {
	list *list.List
	lock sync.Mutex
}

func NewStack() *Stack {
	return &Stack{list.New(), sync.Mutex{}}
}

func (this *Stack) Push(elem interface{}) {
	this.lock.Lock()
	defer this.lock.Unlock()

	this.list.PushBack(elem)
}

func (this *Stack) Pop() (interface{}, bool) {
	this.lock.Lock()
	defer this.lock.Unlock()

	if this.list.Len() == 0 {
		return nil, false
	}

	element := this.list.Back()
	this.list.Remove(element)

	return element.Value, true
}

func (this *Stack) Size() int {
	this.lock.Lock()
	defer this.lock.Unlock()

	return this.list.Len()
}

func (this *Stack) IsEmpty() bool {
	this.lock.Lock()
	defer this.lock.Unlock()

	return (this.list.Len() == 0)
}

// Define Queue class
type Queue struct {
	list *list.List
	lock sync.Mutex
}

func NewQueue() *Queue {
	return &Queue{list.New(), sync.Mutex{}}
}

func (this *Queue) Push(elem interface{}) {
	this.lock.Lock()
	defer this.lock.Unlock()

	this.list.PushFront(elem)
}

func (this *Queue) Pop() (interface{}, bool) {
	this.lock.Lock()
	defer this.lock.Unlock()

	if this.list.Len() == 0 {
		return nil, false
	}

	element := this.list.Front()
	this.list.Remove(element)

	return element.Value, true
}

func (this *Queue) Size() int {
	this.lock.Lock()
	defer this.lock.Unlock()

	return this.list.Len()
}

func (this *Queue) IsEmpty() bool {
	this.lock.Lock()
	defer this.lock.Unlock()

	return (this.list.Len() == 0)
}

func main() {
	s := NewStack()
	s.Push(3)

	if ele, ok := s.Pop(); ok {
		fmt.Printf("Content : %v\n", ele)
		fmt.Printf("Size : %d\n", s.Size())
	}

	q := NewQueue()
	q.Push(4)

	if ele, ok := q.Pop(); ok {
		fmt.Printf("Content : %v\n", ele)
		fmt.Printf("Size : %d\n", s.Size())
	}

}