make application with base logic

internal/common/nullable/value.go

@@ -0,0 +1,42 @@
+package nullable
+
+type Value[T any] struct {
+	value T
+	valid bool
+}
+
+func NewValue[T any](value T) Value[T] {
+	return Value[T]{
+		value: value,
+		valid: true,
+	}
+}
+
+func NewValuePtr[T any](value *T) Value[T] {
+	if value == nil {
+		return Value[T]{}
+	}
+
+	return NewValue(*value)
+}
+
+func (n Value[T]) Value() T {
+	return n.value
+}
+
+func (n Value[T]) Valid() bool {
+	return n.valid
+}
+
+func (n Value[T]) ValutPtr() *T {
+	if n.valid {
+		return &n.value
+	}
+
+	return nil
+}
+
+func (n *Value[T]) Set(value T) {
+	n.valid = true
+	n.value = value
+}