From c43d254d1376c24c76df45bb274dda74ddfa2e19 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Tue, 24 Jan 2017 11:36:43 +0100
Subject: [PATCH] Fix seq().reverse() in c++98

---
 Eigen/src/Core/ArithmeticSequence.h | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/Eigen/src/Core/ArithmeticSequence.h b/Eigen/src/Core/ArithmeticSequence.h
index c5c8bb105..6c10ecc02 100644
--- a/Eigen/src/Core/ArithmeticSequence.h
+++ b/Eigen/src/Core/ArithmeticSequence.h
@@ -43,9 +43,20 @@ struct aseq_reverse_first_type<FirstType,SizeType,IncrType,true,true> {
                            > type;
 };
 
+template<typename SizeType,typename IncrType,typename EnableIf = void>
+struct aseq_reverse_first_type_aux {
+  typedef Index type;
+};
+
+template<typename SizeType,typename IncrType>
+struct aseq_reverse_first_type_aux<SizeType,IncrType,typename internal::enable_if<bool((SizeType::value+IncrType::value)|0x1)>::type> {
+  typedef FixedInt<(SizeType::value-1)*IncrType::value> type;
+};
+
 template<typename FirstType,typename SizeType,typename IncrType>
 struct aseq_reverse_first_type<FirstType,SizeType,IncrType,true,false> {
-  typedef Symbolic::AddExpr<FirstType,Symbolic::ValueExpr<> > type;
+  typedef typename aseq_reverse_first_type_aux<SizeType,IncrType>::type Aux;
+  typedef Symbolic::AddExpr<FirstType,Symbolic::ValueExpr<Aux> > type;
 };
 
 template<typename FirstType,typename SizeType,typename IncrType>