DofObject::old_dof_object can be a unique_ptr

* Make DofObject destructor default, non-protected.
* Cannot use std::make_unique since DofObject copy ctor is private.

Author: jwpeterson

include/base/dof_object.h

@@ -32,6 +32,7 @@
 #include <cstddef>
 #include <cstring>
 #include <vector>
+#include <memory>
 
 namespace libMesh
 {
@@ -64,21 +65,20 @@ class DofObject : public ReferenceCountedObject<DofObject>
    */
   DofObject ();
 
+public:
+
   /**
-   * Destructor. Protected so that you can't destroy one of these
-   * except as a part of a Node or Elem.
+   * Destructor.
    */
-  ~DofObject ();
-
-public:
+  ~DofObject () = default;
 
 #ifdef LIBMESH_ENABLE_AMR
 
   /**
    * This object on the last mesh.  Useful for projecting
    * solutions from one mesh to another.
    */
-  DofObject * old_dof_object;
+  std::unique_ptr<DofObject> old_dof_object;
 
   /**
    * Sets the \p old_dof_object to nullptr
@@ -676,9 +676,6 @@ class DofObject : public ReferenceCountedObject<DofObject>
 // Inline functions
 inline
 DofObject::DofObject () :
-#ifdef LIBMESH_ENABLE_AMR
-  old_dof_object(nullptr),
-#endif
 #ifdef LIBMESH_ENABLE_UNIQUE_ID
   _unique_id (invalid_unique_id),
 #endif
@@ -692,18 +689,6 @@ DofObject::DofObject () :
 
 
 
-inline
-DofObject::~DofObject ()
-{
-  // Free all memory.
-#ifdef LIBMESH_ENABLE_AMR
-  this->clear_old_dof_object ();
-#endif
-  this->clear_dofs ();
-}
-
-
-
 inline
 void DofObject::invalidate_dofs (const unsigned int sys_num)
 {

src/base/dof_object.C

@@ -17,17 +17,12 @@
 
 
 
-// C++ includes
-
 // Local includes
 #include "libmesh/dof_object.h"
 
-
 namespace libMesh
 {
 
-
-
 // ------------------------------------------------------------
 // DofObject class static member -now initialized in header
 const dof_id_type       DofObject::invalid_id;
@@ -36,14 +31,9 @@ const processor_id_type DofObject::invalid_processor_id;
 
 
 
-// ------------------------------------------------------------
-// DofObject class members
 // Copy Constructor
 DofObject::DofObject (const DofObject & dof_obj) :
   ReferenceCountedObject<DofObject>(),
-#ifdef LIBMESH_ENABLE_AMR
-  old_dof_object (nullptr),
-#endif
 #ifdef LIBMESH_ENABLE_UNIQUE_ID
   _unique_id     (dof_obj._unique_id),
 #endif
@@ -56,9 +46,6 @@ DofObject::DofObject (const DofObject & dof_obj) :
   // is intended to be used solely for internal construction of
   // old_dof_object, never for a true deep copy where the newly
   // created object really matches the source object.
-  //
-  // if (dof_obj.old_dof_object)
-  //  this->old_dof_object = new DofObject(*(dof_obj.old_dof_object));
 
   // Check that everything worked
 #ifdef DEBUG
@@ -95,7 +82,10 @@ DofObject & DofObject::operator= (const DofObject & dof_obj)
 #ifdef LIBMESH_ENABLE_AMR
   this->clear_old_dof_object();
 
-  this->old_dof_object = new DofObject(*(dof_obj.old_dof_object));
+  // Note: we can't use std::make_unique here because the DofObject
+  // copy constructor is private, and std::make_unique effectively
+  // calls "placement new" which requires a public constructor.
+  this->old_dof_object = std::unique_ptr<DofObject>(new DofObject(*dof_obj.old_dof_object));
 #endif
 
   _id           = dof_obj._id;
@@ -141,8 +131,7 @@ DofObject & DofObject::operator= (const DofObject & dof_obj)
 
 void  DofObject::clear_old_dof_object ()
 {
-  delete this->old_dof_object;
-  this->old_dof_object = nullptr;
+  this->old_dof_object.reset(nullptr);
 }
 
 
@@ -153,9 +142,10 @@ void DofObject::set_old_dof_object ()
 
   libmesh_assert (!this->old_dof_object);
 
-  // Make a new DofObject, assign a copy of \p this.
-  // Make sure the copy ctor for DofObject works!!
-  this->old_dof_object = new DofObject(*this);
+  // Note: we can't use std::make_unique here because the DofObject
+  // copy constructor is private, and std::make_unique effectively
+  // calls "placement new" which requires a public constructor.
+  this->old_dof_object = std::unique_ptr<DofObject>(new DofObject(*this));
 }
 
 #endif
@@ -644,7 +634,7 @@ void DofObject::unpack_indexing(std::vector<largest_id_type>::const_iterator beg
 #ifdef LIBMESH_ENABLE_AMR
   if (has_old_dof_object)
     {
-      this->old_dof_object = new DofObject();
+      this->old_dof_object = std::unique_ptr<DofObject>(new DofObject());
       this->old_dof_object->unpack_indexing(begin+size);
     }
 #endif