SortableList improvements

- now works as expected with transfer() and assignment from other Lists
  - shrink() method : clears indices and returns underlying List

src/OpenFOAM/containers/Lists/SortableList/SortableList.C

@@ -26,6 +26,11 @@ License
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
+template <class Type>
+Foam::SortableList<Type>::SortableList()
+{}
+
+
 template <class Type>
 Foam::SortableList<Type>::SortableList(const UList<Type>& values)
 :
@@ -34,6 +39,7 @@ Foam::SortableList<Type>::SortableList(const UList<Type>& values)
     sort();
 }
 
+
 template <class Type>
 Foam::SortableList<Type>::SortableList(const xfer<List<Type> >& values)
 :
@@ -83,6 +89,14 @@ void Foam::SortableList<Type>::clear()
 }
 
 
+template <class Type>
+Foam::List<Type>& Foam::SortableList<Type>::shrink()
+{
+    indices_.clear();
+    return static_cast<List<Type>&>(*this);
+}
+
+
 template <class Type>
 void Foam::SortableList<Type>::sort()
 {
@@ -108,6 +122,14 @@ void Foam::SortableList<Type>::sort()
 
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
+template <class Type>
+void Foam::SortableList<Type>::operator=(const UList<Type>& rhs)
+{
+    List<Type>::operator=(rhs);
+    indices_.clear();
+}
+
+
 template <class Type>
 void Foam::SortableList<Type>::operator=(const SortableList<Type>& rhs)
 {

src/OpenFOAM/containers/Lists/SortableList/SortableList.H

@@ -64,6 +64,9 @@ public:
 
     // Constructors
 
+        //- Null constructor, sort later (eg, after assignment or transfer)
+        SortableList();
+
         //- Construct from UList, sorting immediately.
         explicit SortableList(const UList<Type>&);
 
@@ -102,12 +105,19 @@ public:
         //- Clear the list and the indices
         void clear();
 
+        //- Clear the indices and return a reference to the underlying List
+        List<Type>& shrink();
+
         //- (stable) sort the list (if changed after construction time)
-        //  also resizes the indices if required
+        //  also resizes the indices as required
         void sort();
 
     // Member Operators
 
+        //- Assignment from UList operator. Takes linear time.
+        void operator=(const UList<Type>&);
+
+        //- Assignment operator. Takes linear time.
         void operator=(const SortableList<Type>&);
 
 };