~> ccg -f github.com/reusee/cowmap -t Key=string,Value=string -r Map=StrStrMap,New=NewStrStrMap
import "sync"

type StrStrMap struct {
	v atomic.Value
	l sync.Mutex
}

func NewStrStrMap(m map[string]string) *StrStrMap {
	ret := new(StrStrMap)
	ret.v.Store(m)
	return ret
}

func (m *StrStrMap) Set(key string, value string) {
	m.l.Lock()
	defer m.l.Unlock()
	cur := m.v.Load().(map[string]string)
	newMap := make(map[string]string)
	for k, v := range cur {
		newMap[k] = v
	}
	newMap[key] = value
	m.v.Store(newMap)
}

func (m *StrStrMap) Get(key string) string {
	cur := m.v.Load().(map[string]string)
	return cur[key]
}

func (m *StrStrMap) Get2(key string) (value string, ok bool) {
	cur := m.v.Load().(map[string]string)
	value, ok = cur[key]
	return
}

func (m *StrStrMap) Del(key string) {
	m.l.Lock()
	defer m.l.Unlock()
	cur := m.v.Load().(map[string]string)
	newMap := make(map[string]string)
	for k, v := range cur {
		newMap[k] = v
	}
	delete(newMap, key)
	m.v.Store(newMap)
}