STYLE: return const char* in CStringList::data()

- and other code style adjustments

src/OpenFOAM/primitives/strings/lists/CStringList.H

@@ -128,7 +128,7 @@ public:
         inline size_t length() const;
 
         //- The flattened character content, with interspersed nul-chars
-        inline char* data() const;
+        inline const char* data() const;
 
 
     // Edit

src/OpenFOAM/primitives/strings/lists/CStringListI.H

@@ -97,7 +97,7 @@ inline char** Foam::CStringList::strings() const
 }
 
 
-inline char* Foam::CStringList::data() const
+inline const char* Foam::CStringList::data() const
 {
     return data_;
 }

src/OpenFOAM/primitives/strings/lists/CStringListTemplates.C

@@ -31,10 +31,7 @@ Foam::CStringList::CStringList
     const UList<StringType>& input
 )
 :
-    argc_(0),
-    len_(0),
-    argv_(nullptr),
-    data_(nullptr)
+    CStringList()
 {
     reset(input);
 }
@@ -63,12 +60,10 @@ void Foam::CStringList::reset
     {
         len_ += str.size() + 1;
     }
+    --len_; // No final nul in overall count
 
-    argv_ = new char*[input.size()+1];
-    data_ = new char[len_];
-    --len_; // Do not include final nul terminator in overall count
-
-    argv_[argc_] = nullptr;     // extra terminator
+    argv_ = new char*[input.size()+1];  // Extra +1 for terminating nullptr
+    data_ = new char[len_+1];           // Extra +1 for terminating nul char
 
     // Copy contents
     char* ptr = data_;