From c76c8d691789830bbb3efb9d53bbc4dd76bebee1 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Mon, 31 May 2010 22:53:02 +0200
Subject: [PATCH] fix issue #125

---
 Eigen/src/Array/PartialRedux.h | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Eigen/src/Array/PartialRedux.h b/Eigen/src/Array/PartialRedux.h
index 3a052ca8a..8173a1854 100644
--- a/Eigen/src/Array/PartialRedux.h
+++ b/Eigen/src/Array/PartialRedux.h
@@ -160,13 +160,15 @@ template<typename ExpressionType, int Direction> class PartialRedux
   public:
 
     typedef typename ei_traits<ExpressionType>::Scalar Scalar;
+    typedef typename NumTraits<Scalar>::Real RealScalar;
     typedef typename ei_meta_if<ei_must_nest_by_value<ExpressionType>::ret,
         ExpressionType, const ExpressionType&>::ret ExpressionTypeNested;
 
-    template<template<typename _Scalar> class Functor> struct ReturnType
+    template<template<typename _Scalar> class Functor,
+             typename Scalar = typename ei_traits<ExpressionType>::Scalar> struct ReturnType
     {
       typedef PartialReduxExpr<ExpressionType,
-                               Functor<typename ei_traits<ExpressionType>::Scalar>,
+                               Functor<Scalar>,
                                Direction
                               > Type;
     };
@@ -217,7 +219,7 @@ template<typename ExpressionType, int Direction> class PartialRedux
       * Output: \verbinclude PartialRedux_squaredNorm.out
       *
       * \sa MatrixBase::squaredNorm() */
-    const typename ReturnType<ei_member_squaredNorm>::Type squaredNorm() const
+    const typename ReturnType<ei_member_squaredNorm,RealScalar>::Type squaredNorm() const
     { return _expression(); }
 
     /** \returns a row (or column) vector expression of the norm
@@ -227,7 +229,7 @@ template<typename ExpressionType, int Direction> class PartialRedux
       * Output: \verbinclude PartialRedux_norm.out
       *
       * \sa MatrixBase::norm() */
-    const typename ReturnType<ei_member_norm>::Type norm() const
+    const typename ReturnType<ei_member_norm,RealScalar>::Type norm() const
     { return _expression(); }
 
     /** \returns a row (or column) vector expression of the sum