Option is abstract class

defs.h

@@ -880,7 +880,7 @@ struct arglist_t {
   const uint32_t argtype{ARGTYPE_UNKNOWN};
   const QString minvalue;    /* minimum value for numeric options */
   const QString maxvalue;    /* maximum value for numeric options */
-  char* argvalptr{nullptr};         /* !!! internal helper. Not used in definitions !!! */
+  char* unused{nullptr};     /* TODO: delete from initialization lists */
 };
 
 enum ff_type {

option.h

@@ -19,10 +19,10 @@
 #ifndef OPTION_H_INCLUDED_
 #define OPTION_H_INCLUDED_
 
-#include "defs.h"
+#include <QByteArray>  // for QByteArray
+#include <QString>     // for QString, operator!=
 
-
-class Option
+class Option /* Abstract Class */
 {
 public:
   /* Types */
@@ -53,6 +53,10 @@ class Option
   virtual bool isEmpty() const = 0;
   virtual const QString& get() const = 0;
   virtual void set(const QString& s) = 0;
+
+  /* Data Members */
+  // I.25: Prefer empty abstract classes as interfaces to class hierarchies
+  // https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#i25-prefer-empty-abstract-classes-as-interfaces-to-class-hierarchies
 };
 
 class OptionCString : public Option