ENH: add Enum single-parameter operator() to resemble a unary function

src/OpenFOAM/primitives/enums/Enum.H

@@ -211,13 +211,18 @@ public:
         //  Identical to single parameter get()
         inline EnumType operator[](const word& enumName) const;
 
-        //- Return the first name corresponding to the given enumeration.
-        //  Returns an empty word on failure.
+        //- Return the first name corresponding to the given enumeration,
+        //- or an empty word on failure.
         //  Identical to single parameter get()
         inline const word& operator[](const EnumType e) const;
 
-        //- Return the enumeration corresponding to the given name or
-        //- deflt if the name is not found.
+        //- Return the first name corresponding to the given enumeration,
+        //- or an empty word on failure.
+        //  Identical to single parameter get()
+        inline const word& operator()(const EnumType e) const;
+
+        //- Return the enumeration corresponding to the given name,
+        //- or deflt if the name is not found.
         inline EnumType operator()
         (
             const word& enumName,

src/OpenFOAM/primitives/enums/EnumI.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2017-2018 OpenCFD Ltd.
+    \\  /    A nd           | Copyright (C) 2017-2019 OpenCFD Ltd.
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -140,11 +140,21 @@ inline const Foam::word& Foam::Enum<EnumType>::operator[]
 }
 
 
+template<class EnumType>
+inline const Foam::word& Foam::Enum<EnumType>::operator()
+(
+    const EnumType e
+) const
+{
+    return get(e);
+}
+
+
 template<class EnumType>
 inline EnumType Foam::Enum<EnumType>::operator()
 (
     const word& enumName,
-    const EnumType defaultValue
+    const EnumType deflt
 ) const
 {
     const label idx = find(enumName);
@@ -154,7 +164,7 @@ inline EnumType Foam::Enum<EnumType>::operator()
         return EnumType(vals_[idx]);
     }
 
-    return defaultValue;
+    return deflt;
 }