diff --git a/doomsday/libdeng2/include/de/data/bitfield.h b/doomsday/libdeng2/include/de/data/bitfield.h
index b02f364de7..d8a2f82010 100644
--- a/doomsday/libdeng2/include/de/data/bitfield.h
+++ b/doomsday/libdeng2/include/de/data/bitfield.h
@@ -48,6 +48,8 @@ class DENG2_PUBLIC BitField
     BitField(BitField const &other);
     BitField(Block const &data);
 
+    BitField &operator = (BitField const &other);
+
     /**
      * Removes all the elements and the data contained in the bit field.
      */
@@ -79,6 +81,11 @@ class DENG2_PUBLIC BitField
      */
     int bitCount() const;
 
+    /**
+     * Returns the identifiers of all elements.
+     */
+    Ids elementIds() const;
+
     /**
      * Returns the packed data as an array of bytes. Only bitCount() bits are
      * valid; the highest bits of the last byte may be unused (and zero).
diff --git a/doomsday/libdeng2/src/data/bitfield.cpp b/doomsday/libdeng2/src/data/bitfield.cpp
index 1558f0801a..9aef844a68 100644
--- a/doomsday/libdeng2/src/data/bitfield.cpp
+++ b/doomsday/libdeng2/src/data/bitfield.cpp
@@ -128,6 +128,15 @@ BitField::BitField(Block const &data) : d(new Instance(this))
     d->packed = data;
 }
 
+BitField &BitField::operator = (BitField const &other)
+{
+    d->elements  = other.d->elements;
+    d->totalBits = other.d->totalBits;
+    d->lookup    = other.d->lookup;
+    d->packed    = other.d->packed;
+    return *this;
+}
+
 void BitField::clear()
 {
     d->packed.clear();
@@ -200,6 +209,16 @@ int BitField::bitCount() const
     return d->totalBits;
 }
 
+BitField::Ids BitField::elementIds() const
+{
+    Ids ids;
+    foreach(Id id, d->elements.keys())
+    {
+        ids.insert(id);
+    }
+    return ids;
+}
+
 Block BitField::data() const
 {
     return d->packed;