--- deliantra/server/include/util.h	2007/06/04 12:19:08	1.48
+++ deliantra/server/include/util.h	2007/06/24 00:33:54	1.50
@@ -55,7 +55,7 @@
 #include <shstr.h>
 #include <traits.h>
 
-// use a gcc extension for auto declarations until ISO C++ sanctifies them
+// use C0X decltype for auto declarations until ISO C++ sanctifies them (if ever)
 #define auto(var,expr) decltype(expr) var = (expr)
 
 // very ugly macro that basicaly declares and initialises a variable
@@ -407,6 +407,10 @@
   }
 };
 
+// Mostly the same as std::vector, but insert/erase can reorder
+// the elements, making insret/remove O(1) instead of O(n).
+//
+// NOTE: only some forms of erase/insert are available
 template<class T>
 struct unordered_vector : std::vector<T, slice_allocator<T> >
 {
@@ -426,28 +430,41 @@
   }
 };
 
-template<class T, int T::* index>
+// This container blends advantages of linked lists
+// (efficiency) with vectors (random access) by
+// by using an unordered vector and storing the vector
+// index inside the object.
+//
+// + memory-efficient on most 64 bit archs
+// + O(1) insert/remove
+// + free unique (but varying) id for inserted objects
+// + cache-friendly iteration
+// - only works for pointers to structs
+//
+// NOTE: only some forms of erase/insert are available
+typedef int object_vector_index;
+
+template<class T, object_vector_index T::*indexmember>
 struct object_vector : std::vector<T *, slice_allocator<T *> >
 {
   typedef typename object_vector::iterator iterator;
 
   bool contains (const T *obj) const
   {
-    return obj->*index;
+    return obj->*indexmember;
   }
 
   iterator find (const T *obj)
   {
-    return obj->*index
-      ? this->begin () + obj->*index - 1
+    return obj->*indexmember
+      ? this->begin () + obj->*indexmember - 1
       : this->end ();
   }
 
   void insert (T *obj)
   {
-    assert (!(obj->*index));
     push_back (obj);
-    obj->*index = this->size ();
+    obj->*indexmember = this->size ();
   }
 
   void insert (T &obj)
@@ -457,14 +474,13 @@
 
   void erase (T *obj)
   {
-    assert (obj->*index);
-    unsigned int pos = obj->*index;
-    obj->*index = 0;
+    unsigned int pos = obj->*indexmember;
+    obj->*indexmember = 0;
 
     if (pos < this->size ())
       {
         (*this)[pos - 1] = (*this)[this->size () - 1];
-        (*this)[pos - 1]->*index = pos;
+        (*this)[pos - 1]->*indexmember = pos;
       }
 
     this->pop_back ();
@@ -472,7 +488,7 @@
 
   void erase (T &obj)
   {
-    errase (&obj);
+    erase (&obj);
   }
 };