From ce8656f1b2ff3fc3207129b916f08b015406a5f1 Mon Sep 17 00:00:00 2001
From: Patrick Pelissier <patrick.pelissier@gmail.com>
Date: Fri, 13 Jul 2018 10:40:40 +0200
Subject: [PATCH] Update

---
 doc/ISSUES.org | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/doc/ISSUES.org b/doc/ISSUES.org
index e62d541d..a1afe51c 100644
--- a/doc/ISSUES.org
+++ b/doc/ISSUES.org
@@ -1,6 +1,28 @@
 *Long term issues*
 ------------------
 
+* TODO #20: Bucket priority queue                               :ENHANCEMENT:
+
+Add a new kind of priority queue. 
+See https://en.wikipedia.org/wiki/Bucket_queue
+
+Check if it will be better as intrusive or non-intrusive container.
+
+To test if a bucket is empty or not, a bitfield can be used to check if
+the bit associated to the bucket is set or not. To get the highest bucket
+non empty, we can perform a CLZ of the bitset, which shall be much faster than
+perming a linear search of the buckets (algorithm complexity is the same,
+except that we can scan 64 entries at a time).
+
+Check if we can use BITSET, or introduce fixed size BITSET or use ad-hock 
+implementation.
+
+
+* TODO #19: Intrusive Red Black Tree                            :ENHANCEMENT:
+
+ Add intrusive red black tree. 
+
+
 * TODO #18: Missing methods                                     :ENHANCEMENT:
 
 Some containers don't have all the methods they should.