STYLE: add deprecated message to NamedEnum constructor

- this class really should not be used at all anymore.
  Add a message so people recognize can find any occurrences.

applications/test/Enum/Test-Enum.C

@@ -82,6 +82,12 @@ const Foam::Enum<int> otherNames2
 
 std::array<const char*, 2> myarray{ "false", "true" };
 
+
+// Verify compile-time warnings
+// #include "NamedEnum.H"
+// const Foam::NamedEnum<testing::option, 2> bad_legacy;
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 // Main program:
 

src/OpenFOAM/primitives/enums/NamedEnum.H

@@ -99,7 +99,8 @@ public:
     // Constructors
 
         //- Construct from names
-        NamedEnum();
+        NamedEnum()
+        FOAM_DEPRECATED_FOR(2017-05, "Enum instead of using NamedEnum");
 
 
     // Member Functions