From 75b6d2b2f84384457c1031d88fa606116d7016df Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Fri, 25 Jun 2010 13:20:34 +0200
Subject: [PATCH] fix very annoying warning (gcc 4.3): type qualifiers ignored
 on function return type

---
 Eigen/src/Core/DenseCoeffsBase.h     |  7 +++++--
 Eigen/src/Core/arch/SSE/PacketMath.h |  4 ++++
 Eigen/src/Core/util/Meta.h           | 20 ++++++++++++++++++++
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/Eigen/src/Core/DenseCoeffsBase.h b/Eigen/src/Core/DenseCoeffsBase.h
index 7d57d5abc..6802cea24 100644
--- a/Eigen/src/Core/DenseCoeffsBase.h
+++ b/Eigen/src/Core/DenseCoeffsBase.h
@@ -33,8 +33,11 @@ class DenseCoeffsBase : public EigenBase<Derived>
     typedef typename ei_traits<Derived>::Index Index;
     typedef typename ei_traits<Derived>::Scalar Scalar;
     typedef typename ei_packet_traits<Scalar>::type PacketScalar;
-    typedef typename ei_meta_if<ei_has_direct_access<Derived>::ret, const Scalar&, const Scalar>::ret CoeffReturnType;
-    typedef typename ei_makeconst<typename ei_packet_traits<Scalar>::type>::type PacketReturnType;
+    typedef typename ei_meta_if<ei_has_direct_access<Derived>::ret,
+                                const Scalar&,
+                                typename ei_meta_if<ei_is_arithmetic<Scalar>::ret, Scalar, const Scalar>::ret
+                               >::ret CoeffReturnType;
+    typedef typename ei_makeconst_return_type<typename ei_packet_traits<Scalar>::type>::type PacketReturnType;
 
     typedef EigenBase<Derived> Base;
     using Base::rows;
diff --git a/Eigen/src/Core/arch/SSE/PacketMath.h b/Eigen/src/Core/arch/SSE/PacketMath.h
index 754379891..29375bdae 100644
--- a/Eigen/src/Core/arch/SSE/PacketMath.h
+++ b/Eigen/src/Core/arch/SSE/PacketMath.h
@@ -33,6 +33,10 @@ typedef __m128  Packet4f;
 typedef __m128i Packet4i;
 typedef __m128d Packet2d;
 
+template<> struct ei_is_arithmetic<__m128>  { enum { ret = true }; };
+template<> struct ei_is_arithmetic<__m128i> { enum { ret = true }; };
+template<> struct ei_is_arithmetic<__m128d> { enum { ret = true }; };
+
 #define ei_vec4f_swizzle1(v,p,q,r,s) \
   (_mm_castsi128_ps(_mm_shuffle_epi32( _mm_castps_si128(v), ((s)<<6|(r)<<4|(q)<<2|(p)))))
 
diff --git a/Eigen/src/Core/util/Meta.h b/Eigen/src/Core/util/Meta.h
index 318664869..481b0ceb2 100644
--- a/Eigen/src/Core/util/Meta.h
+++ b/Eigen/src/Core/util/Meta.h
@@ -64,6 +64,21 @@ template<typename T> struct ei_cleantype<T&>        { typedef typename ei_cleant
 template<typename T> struct ei_cleantype<const T*>  { typedef typename ei_cleantype<T>::type type; };
 template<typename T> struct ei_cleantype<T*>        { typedef typename ei_cleantype<T>::type type; };
 
+template<typename T> struct ei_is_arithmetic      { enum { ret = false }; };
+template<> struct ei_is_arithmetic<float>         { enum { ret = true }; };
+template<> struct ei_is_arithmetic<double>        { enum { ret = true }; };
+template<> struct ei_is_arithmetic<long double>   { enum { ret = true }; };
+template<> struct ei_is_arithmetic<bool>          { enum { ret = true }; };
+template<> struct ei_is_arithmetic<char>          { enum { ret = true }; };
+template<> struct ei_is_arithmetic<signed char>   { enum { ret = true }; };
+template<> struct ei_is_arithmetic<unsigned char> { enum { ret = true }; };
+template<> struct ei_is_arithmetic<signed short>  { enum { ret = true }; };
+template<> struct ei_is_arithmetic<unsigned short>{ enum { ret = true }; };
+template<> struct ei_is_arithmetic<signed int>    { enum { ret = true }; };
+template<> struct ei_is_arithmetic<unsigned int>  { enum { ret = true }; };
+template<> struct ei_is_arithmetic<signed long>   { enum { ret = true }; };
+template<> struct ei_is_arithmetic<unsigned long> { enum { ret = true }; };
+
 template<typename T> struct ei_makeconst            { typedef const T type;  };
 template<typename T> struct ei_makeconst<const T>   { typedef const T type;  };
 template<typename T> struct ei_makeconst<T&>        { typedef const T& type; };
@@ -71,6 +86,11 @@ template<typename T> struct ei_makeconst<const T&>  { typedef const T& type; };
 template<typename T> struct ei_makeconst<T*>        { typedef const T* type; };
 template<typename T> struct ei_makeconst<const T*>  { typedef const T* type; };
 
+template<typename T> struct ei_makeconst_return_type
+{
+  typedef typename ei_meta_if<ei_is_arithmetic<T>::ret, T, typename ei_makeconst<T>::type>::ret type;
+};
+
 /** \internal Allows to enable/disable an overload
   * according to a compile time condition.
   */