diff --git a/applications/test/HashSet/hashSetTest.C b/applications/test/HashSet/hashSetTest.C
index a3527f7dd7..9625b2e0dc 100644
--- a/applications/test/HashSet/hashSetTest.C
+++ b/applications/test/HashSet/hashSetTest.C
@@ -39,7 +39,7 @@ int main(int argc, char *argv[])
     wordHashSet setA(0);
     HashTable<label, word> tableA;
 
-    HashTable<empty> tableB;
+    HashTable<nil> tableB;
     Map<label> mapA;
 
     setA.insert("kjhk");
@@ -49,9 +49,9 @@ int main(int argc, char *argv[])
     tableA.insert("value2", 2);
     tableA.insert("value3", 3);
 
-    tableB.insert("value4", empty());
-    tableB.insert("value5", empty());
-    tableB.insert("value6", empty());
+    tableB.insert("value4", nil());
+    tableB.insert("value5", nil());
+    tableB.insert("value6", nil());
 
     mapA.set(1, 1);
     mapA.set(2, 2);
@@ -66,7 +66,7 @@ int main(int argc, char *argv[])
     Info<< wordHashSet(setA) << endl;
     Info<< "create from HashTable<T>: ";
     Info<< wordHashSet(tableA) << endl;
-    Info<< "create from HashTable<empty>: ";
+    Info<< "create from HashTable<nil>: ";
     Info<< wordHashSet(tableB) << endl;
 
     Info<< "create from Map<label>: ";
diff --git a/src/OpenFOAM/containers/HashTables/HashSet/HashSet.C b/src/OpenFOAM/containers/HashTables/HashSet/HashSet.C
index 3e4123ae4f..b741bd2b0b 100644
--- a/src/OpenFOAM/containers/HashTables/HashSet/HashSet.C
+++ b/src/OpenFOAM/containers/HashTables/HashSet/HashSet.C
@@ -35,7 +35,7 @@ template<class Key, class Hash>
 template<class T>
 Foam::HashSet<Key, Hash>::HashSet(const HashTable<T, Key, Hash>& ht)
 :
-    HashTable<empty, Key, Hash>(ht.size())
+    HashTable<nil, Key, Hash>(ht.size())
 {
     for
     (
diff --git a/src/OpenFOAM/containers/HashTables/HashSet/HashSet.H b/src/OpenFOAM/containers/HashTables/HashSet/HashSet.H
index 889ede7a7d..0ea8f8c646 100644
--- a/src/OpenFOAM/containers/HashTables/HashSet/HashSet.H
+++ b/src/OpenFOAM/containers/HashTables/HashSet/HashSet.H
@@ -46,7 +46,7 @@ Description
 #define HashSet_H
 
 #include "HashTable.H"
-#include "empty.H"
+#include "nil.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -60,13 +60,13 @@ namespace Foam
 template<class Key=word, class Hash=string::hash>
 class HashSet
 :
-    public HashTable<empty, Key, Hash>
+    public HashTable<nil, Key, Hash>
 {
 
 public:
 
-    typedef typename HashTable<empty, Key, Hash>::iterator iterator;
-    typedef typename HashTable<empty, Key, Hash>::const_iterator const_iterator;
+    typedef typename HashTable<nil, Key, Hash>::iterator iterator;
+    typedef typename HashTable<nil, Key, Hash>::const_iterator const_iterator;
 
 
     // Constructors
@@ -74,19 +74,19 @@ public:
         //- Construct given initial size
         HashSet(label size = 100)
         :
-            HashTable<empty, Key, Hash>(size)
+            HashTable<nil, Key, Hash>(size)
         {}
 
         //- Construct from Istream
         HashSet(Istream& is)
         :
-            HashTable<empty, Key, Hash>(is)
+            HashTable<nil, Key, Hash>(is)
         {}
 
         //- Construct from UList of Key
         HashSet(const UList<Key>& lst)
         :
-            HashTable<empty, Key, Hash>(2*lst.size())
+            HashTable<nil, Key, Hash>(2*lst.size())
         {
             forAll(lst, i)
             {
@@ -97,19 +97,19 @@ public:
         //- Construct as copy
         HashSet(const HashSet<Key, Hash>& hs)
         :
-            HashTable<empty, Key, Hash>(hs)
+            HashTable<nil, Key, Hash>(hs)
         {}
 
         //- Construct by transferring the parameter contents
         HashSet(const Xfer<HashSet<Key, Hash> >& hs)
         :
-            HashTable<empty, Key, Hash>(hs)
+            HashTable<nil, Key, Hash>(hs)
         {}
 
         //- Construct by transferring the parameter contents
-        HashSet(const Xfer<HashTable<empty, Key, Hash> >& hs)
+        HashSet(const Xfer<HashTable<nil, Key, Hash> >& hs)
         :
-            HashTable<empty, Key, Hash>(hs)
+            HashTable<nil, Key, Hash>(hs)
         {}
 
         //- Construct from table of contents of the HashTable
@@ -123,13 +123,13 @@ public:
         //- Insert a new entry
         bool insert(const Key& key)
         {
-            return HashTable<empty, Key, Hash>::insert(key, empty());
+            return HashTable<nil, Key, Hash>::insert(key, nil());
         }
 
-        //- Same as insert (cannot overwrite empty content)
+        //- Same as insert (cannot overwrite nil content)
         bool set(const Key& key)
         {
-            return HashTable<empty, Key, Hash>::insert(key, empty());
+            return HashTable<nil, Key, Hash>::insert(key, nil());
         }
 
 
diff --git a/src/OpenFOAM/containers/HashTables/HashTable/HashTable.H b/src/OpenFOAM/containers/HashTables/HashTable/HashTable.H
index 0ecc044222..47cbc6b4c9 100644
--- a/src/OpenFOAM/containers/HashTables/HashTable/HashTable.H
+++ b/src/OpenFOAM/containers/HashTables/HashTable/HashTable.H
@@ -171,6 +171,9 @@ public:
             //- Return number of elements in table.
             inline label size() const;
 
+            //- Return true if the hash table is empty
+            inline bool empty() const;
+
             //- Return true if hashedEntry is found in table
             bool found(const Key&) const;
 
diff --git a/src/OpenFOAM/containers/HashTables/HashTable/HashTableI.H b/src/OpenFOAM/containers/HashTables/HashTable/HashTableI.H
index 8762d12a9a..03359b2fd1 100644
--- a/src/OpenFOAM/containers/HashTables/HashTable/HashTableI.H
+++ b/src/OpenFOAM/containers/HashTables/HashTable/HashTableI.H
@@ -51,6 +51,13 @@ inline Foam::label Foam::HashTable<T, Key, Hash>::size() const
 }
 
 
+template<class T, class Key, class Hash>
+inline bool Foam::HashTable<T, Key, Hash>::empty() const
+{
+    return (nElmts_ == 0);
+}
+
+
 template<class T, class Key, class Hash>
 inline bool Foam::HashTable<T, Key, Hash>::insert
 (
diff --git a/src/OpenFOAM/containers/HashTables/StaticHashTable/StaticHashTable.H b/src/OpenFOAM/containers/HashTables/StaticHashTable/StaticHashTable.H
index 15044c33e2..2816056383 100644
--- a/src/OpenFOAM/containers/HashTables/StaticHashTable/StaticHashTable.H
+++ b/src/OpenFOAM/containers/HashTables/StaticHashTable/StaticHashTable.H
@@ -164,6 +164,9 @@ public:
             //- Return number of elements in table.
             inline label size() const;
 
+            //- Return true if the hash table is empty
+            inline bool empty() const;
+
             //- Return true if hashed entry is found in table
             bool found(const Key& key) const;
 
diff --git a/src/OpenFOAM/containers/HashTables/StaticHashTable/StaticHashTableI.H b/src/OpenFOAM/containers/HashTables/StaticHashTable/StaticHashTableI.H
index 104cbbf3fe..93317105a8 100644
--- a/src/OpenFOAM/containers/HashTables/StaticHashTable/StaticHashTableI.H
+++ b/src/OpenFOAM/containers/HashTables/StaticHashTable/StaticHashTableI.H
@@ -38,6 +38,13 @@ inline Foam::label Foam::StaticHashTable<T, Key, Hash>::size() const
 }
 
 
+template<class T, class Key, class Hash>
+inline bool Foam::StaticHashTable<T, Key, Hash>::empty() const
+{
+    return (nElmts_ == 0);
+}
+
+
 template<class T, class Key, class Hash>
 inline bool Foam::StaticHashTable<T, Key, Hash>::insert
 (
diff --git a/src/OpenFOAM/containers/LinkedLists/linkTypes/DLListBase/DLListBase.H b/src/OpenFOAM/containers/LinkedLists/linkTypes/DLListBase/DLListBase.H
index 33d55e3186..475109cc77 100644
--- a/src/OpenFOAM/containers/LinkedLists/linkTypes/DLListBase/DLListBase.H
+++ b/src/OpenFOAM/containers/LinkedLists/linkTypes/DLListBase/DLListBase.H
@@ -122,6 +122,9 @@ public:
             //- Return number of elements in list
             inline label size() const;
 
+            //- Return true if the list is empty
+            inline bool empty() const;
+
             //- Return first entry
             inline link* first();
 
diff --git a/src/OpenFOAM/containers/LinkedLists/linkTypes/DLListBase/DLListBaseI.H b/src/OpenFOAM/containers/LinkedLists/linkTypes/DLListBase/DLListBaseI.H
index e30902ce50..6692ce5c52 100644
--- a/src/OpenFOAM/containers/LinkedLists/linkTypes/DLListBase/DLListBaseI.H
+++ b/src/OpenFOAM/containers/LinkedLists/linkTypes/DLListBase/DLListBaseI.H
@@ -81,6 +81,12 @@ inline Foam::label Foam::DLListBase::size() const
 }
 
 
+inline bool Foam::DLListBase::empty() const
+{
+    return (nElmts_ == 0);
+}
+
+
 inline Foam::DLListBase::link*
 Foam::DLListBase::first()
 {
diff --git a/src/OpenFOAM/containers/LinkedLists/linkTypes/SLListBase/SLListBase.H b/src/OpenFOAM/containers/LinkedLists/linkTypes/SLListBase/SLListBase.H
index 4102dee336..06f5960fae 100644
--- a/src/OpenFOAM/containers/LinkedLists/linkTypes/SLListBase/SLListBase.H
+++ b/src/OpenFOAM/containers/LinkedLists/linkTypes/SLListBase/SLListBase.H
@@ -119,6 +119,9 @@ public:
             //- Return number of elements in list
             inline label size() const;
 
+            //- Return true if the list is empty
+            inline bool empty() const;
+
             //- Return first entry
             inline link* first();
 
diff --git a/src/OpenFOAM/containers/LinkedLists/linkTypes/SLListBase/SLListBaseI.H b/src/OpenFOAM/containers/LinkedLists/linkTypes/SLListBase/SLListBaseI.H
index 2d84028e6c..ca069a239d 100644
--- a/src/OpenFOAM/containers/LinkedLists/linkTypes/SLListBase/SLListBaseI.H
+++ b/src/OpenFOAM/containers/LinkedLists/linkTypes/SLListBase/SLListBaseI.H
@@ -71,6 +71,12 @@ inline Foam::label Foam::SLListBase::size() const
 }
 
 
+inline bool Foam::SLListBase::empty() const
+{
+    return (nElmts_ == 0);
+}
+
+
 inline Foam::SLListBase::link*
 Foam::SLListBase::first()
 {
diff --git a/src/OpenFOAM/containers/LinkedLists/user/FIFOStack.H b/src/OpenFOAM/containers/LinkedLists/user/FIFOStack.H
index 04a6791f24..a07b94cbcc 100644
--- a/src/OpenFOAM/containers/LinkedLists/user/FIFOStack.H
+++ b/src/OpenFOAM/containers/LinkedLists/user/FIFOStack.H
@@ -92,15 +92,6 @@ public:
             }
 
 
-        // Check
-
-            //- Is the stack empty
-            bool empty() const
-            {
-                return this->size() == 0;
-            }
-
-
         // Edit
 
             //- Push an element onto the stack
diff --git a/src/OpenFOAM/containers/LinkedLists/user/LIFOStack.H b/src/OpenFOAM/containers/LinkedLists/user/LIFOStack.H
index b8bcde265c..9e60f35f77 100644
--- a/src/OpenFOAM/containers/LinkedLists/user/LIFOStack.H
+++ b/src/OpenFOAM/containers/LinkedLists/user/LIFOStack.H
@@ -92,15 +92,6 @@ public:
             }
 
 
-        // Check
-
-            //- Is the stack empty
-            bool empty() const
-            {
-                return this->size() == 0;
-            }
-
-
         // Edit
 
             //- Push an element onto the stack
diff --git a/src/OpenFOAM/containers/Lists/BiIndirectList/BiIndirectList.H b/src/OpenFOAM/containers/Lists/BiIndirectList/BiIndirectList.H
index 6e60d13d8a..a7827ec6cb 100644
--- a/src/OpenFOAM/containers/Lists/BiIndirectList/BiIndirectList.H
+++ b/src/OpenFOAM/containers/Lists/BiIndirectList/BiIndirectList.H
@@ -75,6 +75,8 @@ public:
         // Access
 
             inline label size() const;
+            inline bool  empty() const;
+
             inline const UList<T>& posList() const;
             inline const UList<T>& negList() const;
             inline const List<label>& addressing() const;
diff --git a/src/OpenFOAM/containers/Lists/BiIndirectList/BiIndirectListI.H b/src/OpenFOAM/containers/Lists/BiIndirectList/BiIndirectListI.H
index 8425cb980d..b30769d107 100644
--- a/src/OpenFOAM/containers/Lists/BiIndirectList/BiIndirectListI.H
+++ b/src/OpenFOAM/containers/Lists/BiIndirectList/BiIndirectListI.H
@@ -49,6 +49,13 @@ inline Foam::label Foam::BiIndirectList<T>::size() const
 }
 
 
+template<class T>
+inline bool Foam::BiIndirectList<T>::empty() const
+{
+    return addressing_.empty();
+}
+
+
 template<class T>
 inline const Foam::UList<T>& Foam::BiIndirectList<T>::posList() const
 {
diff --git a/src/OpenFOAM/containers/Lists/CompactListList/CompactListList.H b/src/OpenFOAM/containers/Lists/CompactListList/CompactListList.H
index 91a6729706..7cf9e31669 100644
--- a/src/OpenFOAM/containers/Lists/CompactListList/CompactListList.H
+++ b/src/OpenFOAM/containers/Lists/CompactListList/CompactListList.H
@@ -126,6 +126,9 @@ public:
             //- Return the primary size, i.e. the number of rows
             inline label size() const;
 
+            //- Return true if the number of rows is zero
+            inline bool empty() const;
+
             //- Return the offset table
             inline const List<label>& offsets() const;
 
diff --git a/src/OpenFOAM/containers/Lists/CompactListList/CompactListListI.H b/src/OpenFOAM/containers/Lists/CompactListList/CompactListListI.H
index 851609ba7c..e2e794356e 100644
--- a/src/OpenFOAM/containers/Lists/CompactListList/CompactListListI.H
+++ b/src/OpenFOAM/containers/Lists/CompactListList/CompactListListI.H
@@ -74,6 +74,13 @@ inline Foam::label Foam::CompactListList<T>::size() const
 }
 
 
+template<class T>
+inline bool Foam::CompactListList<T>::empty() const
+{
+    return offsets_.empty();
+}
+
+
 template<class T>
 inline const Foam::List<Foam::label>& Foam::CompactListList<T>::offsets() const
 {
diff --git a/src/OpenFOAM/containers/Lists/IndirectList/IndirectList.H b/src/OpenFOAM/containers/Lists/IndirectList/IndirectList.H
index 18affc9d06..776d7b65db 100644
--- a/src/OpenFOAM/containers/Lists/IndirectList/IndirectList.H
+++ b/src/OpenFOAM/containers/Lists/IndirectList/IndirectList.H
@@ -69,6 +69,8 @@ public:
         // Access
 
             inline label size() const;
+            inline bool  empty() const;
+
             inline const UList<T>& completeList() const;
             inline const List<label>& addressing() const;
 
diff --git a/src/OpenFOAM/containers/Lists/IndirectList/IndirectListI.H b/src/OpenFOAM/containers/Lists/IndirectList/IndirectListI.H
index 94a8bbf4b3..0ae5311d97 100644
--- a/src/OpenFOAM/containers/Lists/IndirectList/IndirectListI.H
+++ b/src/OpenFOAM/containers/Lists/IndirectList/IndirectListI.H
@@ -47,6 +47,13 @@ inline Foam::label Foam::IndirectList<T>::size() const
 }
 
 
+template<class T>
+inline bool Foam::IndirectList<T>::empty() const
+{
+    return addressing_.empty();
+}
+
+
 template<class T>
 inline const Foam::UList<T>& Foam::IndirectList<T>::completeList() const
 {
diff --git a/src/OpenFOAM/containers/Lists/PackedList/PackedList.H b/src/OpenFOAM/containers/Lists/PackedList/PackedList.H
index ea75d13eda..d2d015ad56 100644
--- a/src/OpenFOAM/containers/Lists/PackedList/PackedList.H
+++ b/src/OpenFOAM/containers/Lists/PackedList/PackedList.H
@@ -166,6 +166,9 @@ public:
             //- Number of packed elements
             inline label size() const;
 
+            //- Return true if the list is empty (i.e., if size() == 0).
+            inline bool empty() const;
+
             //- Get value at index I
             inline unsigned int get(const label i) const;
 
diff --git a/src/OpenFOAM/containers/Lists/PackedList/PackedListI.H b/src/OpenFOAM/containers/Lists/PackedList/PackedListI.H
index 809ae08ab5..dc5f18786e 100644
--- a/src/OpenFOAM/containers/Lists/PackedList/PackedListI.H
+++ b/src/OpenFOAM/containers/Lists/PackedList/PackedListI.H
@@ -117,6 +117,13 @@ inline Foam::label Foam::PackedList<nBits>::size() const
 }
 
 
+template<int nBits>
+inline bool Foam::PackedList<nBits>::empty() const
+{
+    return (size_ == 0);
+}
+
+
 // Get value at i
 template<int nBits>
 inline unsigned int Foam::PackedList<nBits>::get(const label i) const
diff --git a/src/OpenFOAM/containers/Lists/PtrList/PtrList.H b/src/OpenFOAM/containers/Lists/PtrList/PtrList.H
index b90f0f0b6f..86c7ea8f4d 100644
--- a/src/OpenFOAM/containers/Lists/PtrList/PtrList.H
+++ b/src/OpenFOAM/containers/Lists/PtrList/PtrList.H
@@ -158,6 +158,9 @@ public:
             //- Return the number of elements in the PtrList
             inline label size() const;
 
+            //- Return true if the PtrList is empty (i.e., if size() == 0).
+            inline bool empty() const;
+
 
         // Edit
 
diff --git a/src/OpenFOAM/containers/Lists/PtrList/PtrListI.H b/src/OpenFOAM/containers/Lists/PtrList/PtrListI.H
index fe983406cf..8dfbe2686a 100644
--- a/src/OpenFOAM/containers/Lists/PtrList/PtrListI.H
+++ b/src/OpenFOAM/containers/Lists/PtrList/PtrListI.H
@@ -38,6 +38,13 @@ inline Foam::label Foam::PtrList<T>::size() const
 }
 
 
+template<class T>
+inline bool Foam::PtrList<T>::empty() const
+{
+    return ptrs_.empty();
+}
+
+
 template<class T>
 inline bool Foam::PtrList<T>::set(const label i) const
 {
diff --git a/src/OpenFOAM/primitives/empty/empty.H b/src/OpenFOAM/primitives/nil/nil.H
similarity index 80%
rename from src/OpenFOAM/primitives/empty/empty.H
rename to src/OpenFOAM/primitives/nil/nil.H
index ba1628421c..c6fd97eaaf 100644
--- a/src/OpenFOAM/primitives/empty/empty.H
+++ b/src/OpenFOAM/primitives/nil/nil.H
@@ -23,20 +23,15 @@ License
     Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 
 Class
-    Foam::empty
+    Foam::nil
 
 Description
-    A class without storage. Used, for example, in HashSet.
-
-SourceFiles
-    emptyI.H
-    empty.C
-    emptyIO.C
+    A class without any storage. Used, for example, in HashSet.
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef empty_H
-#define empty_H
+#ifndef nil_H
+#define nil_H
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -49,17 +44,17 @@ class Ostream;
 
 // Forward declaration of friend functions and operators
 
-class empty;
+class nil;
 
-Istream& operator>>(Istream& is, empty&);
-Ostream& operator<<(Ostream& os, const empty&);
+Istream& operator>>(Istream&, nil&);
+Ostream& operator<<(Ostream&, const nil&);
 
 
 /*---------------------------------------------------------------------------*\
-                           Class empty Declaration
+                             Class nil Declaration
 \*---------------------------------------------------------------------------*/
 
-class empty
+class nil
 {
 
 public:
@@ -67,22 +62,22 @@ public:
     // Constructors
 
         //- Construct null
-        empty()
+        nil()
         {}
 
         //- Construct from Istream
-        empty(Istream&)
+        nil(Istream&)
         {}
 
 
-    // IOstream Operator
+    // IOstream Operators
 
-        friend Istream& operator>>(Istream& is, empty&)
+        friend Istream& operator>>(Istream& is, nil&)
         {
             return is;
         }
 
-        friend Ostream& operator<<(Ostream& os, const empty&)
+        friend Ostream& operator<<(Ostream& os, const nil&)
         {
             return os;
         }