From 128ff9cf0746798e6cfbab24918933cc5f183777 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Thu, 23 Feb 2012 11:38:18 +0100
Subject: [PATCH] declare a ReverseInnerIterator in sparse CwiseBinaryOp. These
 ReverseInnerIterator should probably be removed anyway since we currently
 don't have real use cases for them. The only one in TriangularSolver could be
 advantageously replaced by a binary search.

---
 Eigen/src/SparseCore/SparseCwiseBinaryOp.h | 1 +
 Eigen/src/SparseCore/TriangularSolver.h    | 1 +
 2 files changed, 2 insertions(+)

diff --git a/Eigen/src/SparseCore/SparseCwiseBinaryOp.h b/Eigen/src/SparseCore/SparseCwiseBinaryOp.h
index 5080292b8..22c227edd 100644
--- a/Eigen/src/SparseCore/SparseCwiseBinaryOp.h
+++ b/Eigen/src/SparseCore/SparseCwiseBinaryOp.h
@@ -63,6 +63,7 @@ class CwiseBinaryOpImpl<BinaryOp, Lhs, Rhs, Sparse>
 {
   public:
     class InnerIterator;
+    class ReverseInnerIterator;
     typedef CwiseBinaryOp<BinaryOp, Lhs, Rhs> Derived;
     EIGEN_SPARSE_PUBLIC_INTERFACE(Derived)
     CwiseBinaryOpImpl()
diff --git a/Eigen/src/SparseCore/TriangularSolver.h b/Eigen/src/SparseCore/TriangularSolver.h
index 8ed471e45..7f27df726 100644
--- a/Eigen/src/SparseCore/TriangularSolver.h
+++ b/Eigen/src/SparseCore/TriangularSolver.h
@@ -156,6 +156,7 @@ struct sparse_solve_triangular_selector<Lhs,Rhs,Mode,Upper,ColMajor>
         {
           if(!(Mode & UnitDiag))
           {
+            // TODO replace this by a binary search. make sure the binary search is safe for partially sorted elements
             typename Lhs::ReverseInnerIterator it(lhs, i);
             while(it && it.index()!=i)
               --it;