diff --git a/safety/rwmap.go b/safety/rwmap.go
new file mode 100644
index 0000000..4a84153
--- /dev/null
+++ b/safety/rwmap.go
@@ -0,0 +1,67 @@
+package safety
+
+import "sync"
+
+type RWMap[K comparable, V any] struct {
+	m   map[K]V
+	mux sync.RWMutex
+}
+
+func NewRWMap[K comparable, V any](val ...map[K]V) *RWMap[K, V] {
+	var m map[K]V
+	if len(val) < 1 {
+		m = make(map[K]V)
+	} else {
+		m = val[0]
+	}
+	return &RWMap[K, V]{m: m, mux: sync.RWMutex{}}
+}
+
+func (v *RWMap[K, V]) Store(key K, val V) {
+	v.mux.Lock()
+	defer v.mux.Unlock()
+	v.m[key] = val
+}
+
+func (v *RWMap[K, V]) Load(key K) (V, bool) {
+	v.mux.RLock()
+	defer v.mux.RUnlock()
+	val, ok := v.m[key]
+	return val, ok
+}
+
+func (v *RWMap[K, V]) Del(keys ...K) {
+	v.mux.Lock()
+	defer v.mux.Unlock()
+	for _, key := range keys {
+		delete(v.m, key)
+	}
+}
+
+func (v *RWMap[K, V]) Raw() map[K]V {
+	v.mux.RLock()
+	defer v.mux.RUnlock()
+	return v.m
+}
+
+func (v *RWMap[K, V]) Len() int {
+	v.mux.RLock()
+	defer v.mux.RUnlock()
+	return len(v.m)
+}
+
+func (v *RWMap[K, V]) Range(fn func(K, V) bool) {
+	v.mux.RLock()
+	defer v.mux.RUnlock()
+	for key, val := range v.m {
+		if !fn(key, val) {
+			break
+		}
+	}
+}
+
+func (v *RWMap[K, V]) Set(m map[K]V) {
+	v.mux.Lock()
+	defer v.mux.Unlock()
+	v.m = m
+}
diff --git a/safety/slice.go b/safety/slice.go
index 6be8ee0..84b5a41 100644
--- a/safety/slice.go
+++ b/safety/slice.go
@@ -17,7 +17,23 @@ func NewSlice[T any](a []T) *Slice[T] {
 func (r *Slice[T]) Append(t ...T) {
 	r.mu.Lock()
 	defer r.mu.Unlock()
-	ts := append(r.Load(), t...)
+	ts := append(r.Var.Load(), t...)
 	r.Store(ts)
-
+}
+
+func (r *Slice[T]) Set(index int, val T) {
+	v := r.Var.Load()
+	if index >= len(v) {
+		return
+	}
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	v[index] = val
+}
+
+func (r *Slice[T]) Load() (a []T) {
+	v := r.Var.Load()
+	a = make([]T, len(v))
+	copy(a, v)
+	return
 }