Minor stylistic improvements

src/DataTree.hh

@@ -106,7 +106,7 @@ protected:
   static string packageDir(const string &package);
 
 private:
-  const static int constants_precision{16};
+  constexpr static int constants_precision{16};
 
   //! The list of nodes
   vector<unique_ptr<ExprNode>> node_list;

src/ExprNode.hh

@@ -181,8 +181,8 @@ class ExprNode
       //! Used for caching of first order derivatives (when non-null)
       map<int, expr_t> derivatives;
 
-      const static int min_cost_matlab{40*90};
-      const static int min_cost_c{40*4};
+      constexpr static int min_cost_matlab{40*90};
+      constexpr static int min_cost_c{40*4};
       inline static int min_cost(bool is_matlab) { return(is_matlab ? min_cost_matlab : min_cost_c); };
 
       //! Cost of computing current node

src/ExternalFunctionsTable.hh

@@ -53,11 +53,11 @@ public:
   };
   using external_function_table_type = map<int, external_function_options>;
   //! Symbol ID used when no external function exists that calculates the derivative
-  const static int IDNotSet = -1;
+  constexpr static int IDNotSet = -1;
   //! Symbol ID used when the derivative is obtained from the top-level function
-  const static int IDSetButNoNameProvided = -2;
+  constexpr static int IDSetButNoNameProvided = -2;
   //! Default number of arguments when nargs is not specified
-  const static int defaultNargs = 1;
+  constexpr static int defaultNargs = 1;
 private:
   //! Map containing options provided to external_functions()
   external_function_table_type externalFunctionTable;

src/Statement.cc

@@ -143,8 +143,8 @@ void
 OptionsList::writeOutput(ostream &output, const string &option_group) const
 {
   // Initialize option_group as an empty struct iff the field does not exist!
-  unsigned idx = option_group.find_last_of(".");
-  if (idx < UINT_MAX)
+  size_t idx = option_group.find_last_of(".");
+  if (idx != string::npos)
     {
       output << "if ~isfield(" << option_group.substr(0, idx) << ",'" << option_group.substr(idx+1) << "')" << endl;
       output << "    " << option_group << " = struct();" << endl;