added Atom[T] to have atomic manipulation of composite values

atom.go

@@ -0,0 +1,21 @@
+package hodu
+
+import "sync/atomic"
+
+type Atom[T any] struct {
+	val atomic.Value
+}
+
+func (av* Atom[T]) Set(v T) {
+	av.val.Store(v)
+}
+
+func (av* Atom[T]) Get() T {
+	var v interface{}
+	v = av.val.Load()
+	if v == nil { 
+		var t T
+		return t // return the zero-value
+	}
+	return v.(T)
+}