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diff --git a/include/c++/util/radix.h b/include/c++/util/radix.h
new file mode 100644
index 0000000..b75d27e
--- /dev/null
+++ b/include/c++/util/radix.h
@@ -0,0 +1,126 @@
+// Generic radix trees, which supports mapping integer keys to objects.
+//
+// Written by Scott Wood <scott@buserror.net>.
+// 
+// This software is provided 'as-is', without any express or implied warranty.
+// In no event will the authors or contributors be held liable for any damages
+// arising from the use of this software.
+// 
+// This software is in the public domain.
+
+#ifndef _UTIL_RADIX_H
+#define _UTIL_RADIX_H
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include <lowlevel/bitops.h>
+
+namespace Util {
+	// Each leaf node in the tree will contain 2**radix_bits handles.
+	// Each directory node will contain 2**dir_bits pointers.
+	template <typename T, int radix_bits, int dir_bits = radix_bits>
+	class RadixTree {
+		typedef unsigned int Key;
+
+		enum {
+			node_size = 1 << radix_bits,
+			dir_size = 1 << dir_bits,
+			long_bits = sizeof(unsigned long) * 8,
+		};
+		
+		struct Node {
+			const int shift;
+			
+		protected:
+			Node(int SHIFT) : shift(SHIFT)
+			{
+			}
+		};
+		
+		struct LeafNode : public Node {
+			T handles[node_size];
+			
+			LeafNode() : Node(0)
+			{
+				shift = 0;
+				memset(handles, 0, sizeof(handles));
+			}
+		};
+		
+		struct DirNode : public Node {
+			Node *ptrs[node_size];
+
+			DirNode(int shift) : Node(shift)
+			{
+				memset(ptrs, 0, sizeof(ptrs));
+			}
+		};
+	
+		Node *toplevel;
+		
+		static int key_to_dir_offset(Key key, int shift)
+		{
+			return (key >> shift) & (dir_size - 1);
+		}
+
+		static uint key_to_offset(Key key)
+		{
+			return key & (node_size - 1);
+		}
+
+	public:
+		T *lookup(Key key, bool add = false)
+		{
+			int next_shift = toplevel->shift == 0 ? radix_bits : dir_bits;
+			
+			while (unlikely(key_to_dir_offset(key, toplevel->shift +
+			                                       next_shift) != 0))
+			{
+				if (!add)
+					return NULL;
+				
+				Node *new_node = new DirNode(toplevel->shift + next_shift);
+				new_node->ptrs[0] = toplevel;
+				toplevel = new_node;
+				next_shift = dir_bits;
+			}
+			
+			Node *node = toplevel;
+			
+			while (node->shift >= radix_bits) {
+				int off = key_to_dir_offset(key, node->shift);
+				NodeBase *new_node = node[off];
+				
+				shift == 0 ? new LeafNode
+				                                : new DirNode(shift);
+				void *new_node = static_cast<void **>(node)[off];
+				
+				if (!new_node) {
+					if (!add)
+						return NULL;
+					
+					new_node = Mem::alloc_pages(1);
+					memset(new_node, 0, Arch::page_size);
+					static_cast<void **>(node)[off] = new_node;
+				}
+				
+				shift -= dir_shift;
+				node = new_node;
+			}
+			
+			assert(shift == 0);
+			return static_cast<T *>(node) + key_to_offset(key, 0);
+		}
+		
+		RadixTree()
+		{
+			toplevel = new LeafNode;
+			memset(toplevel, 0, Arch::page_size);
+			depth = 0;
+		}
+	};
+}
+
+#endif