From 4812071ec37e6b640a8f832ab57639826544655f Mon Sep 17 00:00:00 2001
From: Michael Neumann <mneumann@ntecs.de>
Date: Tue, 20 Oct 2015 23:31:44 +0200
Subject: [PATCH] Add TODO

---
 src/mark_matrix.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/mark_matrix.rs b/src/mark_matrix.rs
index e5ff07b..d6e3eb7 100644
--- a/src/mark_matrix.rs
+++ b/src/mark_matrix.rs
@@ -12,6 +12,8 @@ pub struct MarkMatrix {
     marks: SquareMatrix<Mark>
 }
 
+// XXX: Use two bitmatrices. Each row has a fixed number of u64 integers. Use bit-search
+
 impl MarkMatrix {
     pub fn new(n: usize) -> MarkMatrix {
         MarkMatrix {marks: SquareMatrix::from_row_vec(n, (0..n*n).map(|_| Mark::None).collect())}