iox-eclipse-iceoryx#992 Use enum class

Signed-off-by: Mathias Kraus <mathias.kraus@apex.ai>

iceoryx_hoofs/test/moduletests/test_cxx_helplets.cpp

@@ -1,5 +1,5 @@
 // Copyright (c) 2019 by Robert Bosch GmbH. All rights reserved.
-// Copyright (c) 2021 by Apex AI Inc. All rights reserved.
+// Copyright (c) 2021 - 2022 by Apex AI Inc. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -25,13 +25,13 @@
 
 namespace
 {
-enum A
+enum class A
 {
     A1 = 13,
     A2
 };
 
-enum B
+enum class B
 {
     B1 = 42,
     B2
@@ -47,10 +47,10 @@ constexpr B from<A, B>(A e) noexcept
 {
     switch (e)
     {
-    case A1:
-        return B1;
-    case A2:
-        return B2;
+    case A::A1:
+        return B::B1;
+    case A::A2:
+        return B::B2;
     }
 }