From e2097c55f8b130cac62d52af2cd7d8717ec0d5c1 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Mon, 31 May 2010 22:46:18 +0200
Subject: [PATCH] fix issue #125 - *norm() return RealScalar and not Scalar

---
 Eigen/src/Array/VectorwiseOp.h | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/Eigen/src/Array/VectorwiseOp.h b/Eigen/src/Array/VectorwiseOp.h
index b809283a7..f495aae40 100644
--- a/Eigen/src/Array/VectorwiseOp.h
+++ b/Eigen/src/Array/VectorwiseOp.h
@@ -178,14 +178,16 @@ template<typename ExpressionType, int Direction> class VectorwiseOp
   public:
 
     typedef typename ExpressionType::Scalar Scalar;
+    typedef typename ExpressionType::RealScalar RealScalar;
     typedef typename ExpressionType::Index Index;
     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;
     };
@@ -285,7 +287,7 @@ template<typename ExpressionType, int Direction> class VectorwiseOp
       * Output: \verbinclude PartialRedux_squaredNorm.out
       *
       * \sa DenseBase::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
@@ -295,7 +297,7 @@ template<typename ExpressionType, int Direction> class VectorwiseOp
       * Output: \verbinclude PartialRedux_norm.out
       *
       * \sa DenseBase::norm() */
-    const typename ReturnType<ei_member_norm>::Type norm() const
+    const typename ReturnType<ei_member_norm,RealScalar>::Type norm() const
     { return _expression(); }
 
 
@@ -304,7 +306,7 @@ template<typename ExpressionType, int Direction> class VectorwiseOp
       * blue's algorithm.
       *
       * \sa DenseBase::blueNorm() */
-    const typename ReturnType<ei_member_blueNorm>::Type blueNorm() const
+    const typename ReturnType<ei_member_blueNorm,RealScalar>::Type blueNorm() const
     { return _expression(); }
 
 
@@ -313,7 +315,7 @@ template<typename ExpressionType, int Direction> class VectorwiseOp
       * underflow and overflow.
       *
       * \sa DenseBase::stableNorm() */
-    const typename ReturnType<ei_member_stableNorm>::Type stableNorm() const
+    const typename ReturnType<ei_member_stableNorm,RealScalar>::Type stableNorm() const
     { return _expression(); }
 
 
@@ -322,7 +324,7 @@ template<typename ExpressionType, int Direction> class VectorwiseOp
       * underflow and overflow using a concatenation of hypot() calls.
       *
       * \sa DenseBase::hypotNorm() */
-    const typename ReturnType<ei_member_hypotNorm>::Type hypotNorm() const
+    const typename ReturnType<ei_member_hypotNorm,RealScalar>::Type hypotNorm() const
     { return _expression(); }
 
     /** \returns a row (or column) vector expression of the sum