ENH: output Enum name list without leading number

- not usually of any interest.
  Unifies code for Ostream and std::ostream operators

src/OpenFOAM/primitives/enums/Enum.C

@@ -138,7 +138,7 @@ template<class EnumType>
 bool Foam::Enum<EnumType>::read
 (
     Istream& is,
-    EnumType& e,
+    EnumType& val,
     const bool mandatory
 ) const
 {
@@ -148,7 +148,7 @@ bool Foam::Enum<EnumType>::read
 
     if (idx >= 0)
     {
-        e = EnumType(vals_[idx]);
+        val = EnumType(vals_[idx]);
         return true;
     }
 
@@ -266,17 +266,4 @@ bool Foam::Enum<EnumType>::readEntry
 }
 
 
-template<class EnumType>
-bool Foam::Enum<EnumType>::readIfPresent
-(
-    const word& key,
-    const dictionary& dict,
-    EnumType& val
-) const
-{
-    // Reading is non-mandatory
-    return readEntry(key, dict, val, false);
-}
-
-
 // ************************************************************************* //

src/OpenFOAM/primitives/enums/Enum.H

@@ -50,7 +50,7 @@ SourceFiles
 namespace Foam
 {
 
-// Forward declarations
+// Forward Declarations
 class dictionary;
 template<class EnumType> class Enum;
 
@@ -85,8 +85,8 @@ public:
 
     // Constructors
 
-        //- Construct null (empty list)
-        Enum() = default;
+        //- Default construct, an empty list
+        Enum() noexcept = default;
 
         //- Construct from a values/names list.
         //  Duplicate values are permitted (eg, for aliases).
@@ -205,7 +205,7 @@ public:
         //  Default search: non-recursive with patterns.
         //
         //  \return true if the entry was found.
-        bool readIfPresent
+        inline bool readIfPresent
         (
             const word& key,        //!< Lookup key. Uses LITERAL (not REGEX)
             const dictionary& dict, //!< dictionary
@@ -231,9 +231,10 @@ public:
         //  A noop if the enumeration wasn't found.
         inline void write(const EnumType e, Ostream& os) const;
 
-        //- Write the names as a list to an Ostream.
-        //  Default is without line-breaks.
-        inline Ostream& writeList(Ostream& os, const label shortLen=0) const;
+        //- Write enumeration names as a list without line-breaks
+        //- to an output stream.
+        template<class OS>
+        inline OS& writeList(OS& os, const label ununsed=0) const;
 
 
     // Member Operators

src/OpenFOAM/primitives/enums/EnumI.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2017-2019 OpenCFD Ltd.
+    Copyright (C) 2017-2020 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -113,13 +113,15 @@ inline const Foam::word& Foam::Enum<EnumType>::get(const EnumType e) const
 
 
 template<class EnumType>
-inline Foam::Ostream& Foam::Enum<EnumType>::writeList
+inline bool Foam::Enum<EnumType>::readIfPresent
 (
-    Ostream& os,
-    const label shortLen
+    const word& key,
+    const dictionary& dict,
+    EnumType& val
 ) const
 {
-    return keys_.writeList(os, shortLen);
+    // Reading is non-mandatory
+    return readEntry(key, dict, val, false);
 }
 
 
@@ -135,6 +137,24 @@ inline void Foam::Enum<EnumType>::write(const EnumType e, Ostream& os) const
 }
 
 
+template<class EnumType>
+template<class OS>
+inline OS& Foam::Enum<EnumType>::writeList(OS& os, const label) const
+{
+    unsigned i = 0;
+
+    os << '(';
+    for (const word& k : keys_)
+    {
+        if (i++) os << ' ';
+        os << k;
+    }
+    os << ')';
+
+    return os;
+}
+
+
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 template<class EnumType>
@@ -194,7 +214,7 @@ inline Foam::Ostream& Foam::operator<<
     const Enum<EnumType>& list
 )
 {
-    return list.names().writeList(os, 0);
+    return list.writeList(os);
 }
 
 
@@ -205,19 +225,7 @@ inline std::ostream& Foam::operator<<
     const Enum<EnumType>& list
 )
 {
-    os << '(';
-
-    unsigned i = 0;
-
-    for (const word& k : list.names())
-    {
-        if (i++) os << ' ';
-        os << k;
-    }
-
-    os << ')';
-
-    return os;
+    return list.writeList(os);
 }