Review abastract_object class

Author: gammasoft71

src/xtd.core/CMakeLists.txt

@@ -1286,7 +1286,6 @@ add_sources(
 )
 add_sources(
   "src/xtd/environment_version.cpp"
-  "src/xtd/abstract.cpp"
   "src/xtd/access_violation_exception.cpp"
   "src/xtd/register_any_stringer.cpp"
   "src/xtd/attribute.cpp"

src/xtd.core/include/xtd/abstract_object.hpp

@@ -25,18 +25,17 @@ namespace xtd {
   /// };
   /// ```
   class abstract_object : public xtd::object {
-  public:
-    /// @cond
-    ~abstract_object() override = 0;
-    /// @endcond
-    
   protected:
     /// @name Protected Constructors
 
     /// @{
     /// @brief Initializes a new instance of the xtd::abstract_object class.
     abstract_object() = default;
     /// @}
+
+    /// @cond
+    ~abstract_object() override = default;
+    /// @endcond
   };
 
   /// @brief This keyword is used to represents an abstract class.