diff --git a/Eigen/src/Core/Random.h b/Eigen/src/Core/Random.h
index 0b304e75b..fab6889dc 100644
--- a/Eigen/src/Core/Random.h
+++ b/Eigen/src/Core/Random.h
@@ -17,7 +17,6 @@ namespace Eigen {
 namespace internal {
 
 template<typename Scalar> struct scalar_random_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_random_op)
   inline const Scalar operator() () const { return random<Scalar>(); }
 };
 
diff --git a/Eigen/src/Core/VectorwiseOp.h b/Eigen/src/Core/VectorwiseOp.h
index cf8b27fd9..b004f76ce 100644
--- a/Eigen/src/Core/VectorwiseOp.h
+++ b/Eigen/src/Core/VectorwiseOp.h
@@ -88,7 +88,6 @@ template<typename A,typename B> struct partial_redux_dummy_func;
 #define EIGEN_MAKE_PARTIAL_REDUX_FUNCTOR(MEMBER,COST,VECTORIZABLE,BINARYOP)                \
   template <typename ResultType,typename Scalar>                                                            \
   struct member_##MEMBER {                                                                  \
-    EIGEN_EMPTY_STRUCT_CTOR(member_##MEMBER)                                                \
     typedef ResultType result_type;                                                         \
     typedef BINARYOP<Scalar,Scalar> BinaryOp;   \
     template<int Size> struct Cost { enum { value = COST }; };             \
diff --git a/Eigen/src/Core/arch/Default/TypeCasting.h b/Eigen/src/Core/arch/Default/TypeCasting.h
index b71cbdf34..dc779a725 100644
--- a/Eigen/src/Core/arch/Default/TypeCasting.h
+++ b/Eigen/src/Core/arch/Default/TypeCasting.h
@@ -19,7 +19,6 @@ namespace internal {
 
 template<>
 struct scalar_cast_op<float, Eigen::half> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cast_op)
   typedef Eigen::half result_type;
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half operator() (const float& a) const {
     #if (defined(EIGEN_HAS_CUDA_FP16) && defined(EIGEN_CUDA_ARCH) && EIGEN_CUDA_ARCH >= 300) || \
@@ -38,7 +37,6 @@ struct functor_traits<scalar_cast_op<float, Eigen::half> >
 
 template<>
 struct scalar_cast_op<int, Eigen::half> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cast_op)
   typedef Eigen::half result_type;
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half operator() (const int& a) const {
     #if (defined(EIGEN_HAS_CUDA_FP16) && defined(EIGEN_CUDA_ARCH) && EIGEN_CUDA_ARCH >= 300) || \
@@ -57,7 +55,6 @@ struct functor_traits<scalar_cast_op<int, Eigen::half> >
 
 template<>
 struct scalar_cast_op<Eigen::half, float> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cast_op)
   typedef float result_type;
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE float operator() (const Eigen::half& a) const {
     #if (defined(EIGEN_HAS_CUDA_FP16) && defined(EIGEN_CUDA_ARCH) && EIGEN_CUDA_ARCH >= 300) || \
@@ -76,7 +73,6 @@ struct functor_traits<scalar_cast_op<Eigen::half, float> >
 
 template<>
 struct scalar_cast_op<float, Eigen::bfloat16> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cast_op)
   typedef Eigen::bfloat16 result_type;
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::bfloat16 operator() (const float& a) const {
     return Eigen::bfloat16(a);
@@ -90,7 +86,6 @@ struct functor_traits<scalar_cast_op<float, Eigen::bfloat16> >
 
 template<>
 struct scalar_cast_op<int, Eigen::bfloat16> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cast_op)
   typedef Eigen::bfloat16 result_type;
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::bfloat16 operator() (const int& a) const {
     return Eigen::bfloat16(static_cast<float>(a));
@@ -104,7 +99,6 @@ struct functor_traits<scalar_cast_op<int, Eigen::bfloat16> >
 
 template<>
 struct scalar_cast_op<Eigen::bfloat16, float> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cast_op)
   typedef float result_type;
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE float operator() (const Eigen::bfloat16& a) const {
     return static_cast<float>(a);
diff --git a/Eigen/src/Core/arch/NEON/UnaryFunctors.h b/Eigen/src/Core/arch/NEON/UnaryFunctors.h
index 131746dbd..67f9dcff0 100644
--- a/Eigen/src/Core/arch/NEON/UnaryFunctors.h
+++ b/Eigen/src/Core/arch/NEON/UnaryFunctors.h
@@ -20,7 +20,6 @@ namespace internal {
   */
 template <>
 struct scalar_logistic_op<Eigen::half> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_logistic_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
   Eigen::half operator()(const Eigen::half& x) const {
     // Convert to float and call scalar_logistic_op<float>.
diff --git a/Eigen/src/Core/functors/AssignmentFunctors.h b/Eigen/src/Core/functors/AssignmentFunctors.h
index 6bf755fc9..c9d80e6dc 100644
--- a/Eigen/src/Core/functors/AssignmentFunctors.h
+++ b/Eigen/src/Core/functors/AssignmentFunctors.h
@@ -22,9 +22,8 @@ namespace internal {
   */
 template<typename DstScalar,typename SrcScalar> struct assign_op {
 
-  EIGEN_EMPTY_STRUCT_CTOR(assign_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void assignCoeff(DstScalar& a, const SrcScalar& b) const { a = b; }
-  
+
   template<int Alignment, typename Packet>
   EIGEN_STRONG_INLINE void assignPacket(DstScalar* a, const Packet& b) const
   { internal::pstoret<DstScalar,Packet,Alignment>(a,b); }
@@ -47,9 +46,8 @@ struct functor_traits<assign_op<DstScalar,SrcScalar> > {
   */
 template<typename DstScalar,typename SrcScalar> struct add_assign_op {
 
-  EIGEN_EMPTY_STRUCT_CTOR(add_assign_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void assignCoeff(DstScalar& a, const SrcScalar& b) const { a += b; }
-  
+
   template<int Alignment, typename Packet>
   EIGEN_STRONG_INLINE void assignPacket(DstScalar* a, const Packet& b) const
   { internal::pstoret<DstScalar,Packet,Alignment>(a,internal::padd(internal::ploadt<Packet,Alignment>(a),b)); }
@@ -68,9 +66,8 @@ struct functor_traits<add_assign_op<DstScalar,SrcScalar> > {
   */
 template<typename DstScalar,typename SrcScalar> struct sub_assign_op {
 
-  EIGEN_EMPTY_STRUCT_CTOR(sub_assign_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void assignCoeff(DstScalar& a, const SrcScalar& b) const { a -= b; }
-  
+
   template<int Alignment, typename Packet>
   EIGEN_STRONG_INLINE void assignPacket(DstScalar* a, const Packet& b) const
   { internal::pstoret<DstScalar,Packet,Alignment>(a,internal::psub(internal::ploadt<Packet,Alignment>(a),b)); }
@@ -90,9 +87,8 @@ struct functor_traits<sub_assign_op<DstScalar,SrcScalar> > {
 template<typename DstScalar, typename SrcScalar=DstScalar>
 struct mul_assign_op {
 
-  EIGEN_EMPTY_STRUCT_CTOR(mul_assign_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void assignCoeff(DstScalar& a, const SrcScalar& b) const { a *= b; }
-  
+
   template<int Alignment, typename Packet>
   EIGEN_STRONG_INLINE void assignPacket(DstScalar* a, const Packet& b) const
   { internal::pstoret<DstScalar,Packet,Alignment>(a,internal::pmul(internal::ploadt<Packet,Alignment>(a),b)); }
@@ -111,9 +107,8 @@ struct functor_traits<mul_assign_op<DstScalar,SrcScalar> > {
   */
 template<typename DstScalar, typename SrcScalar=DstScalar> struct div_assign_op {
 
-  EIGEN_EMPTY_STRUCT_CTOR(div_assign_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void assignCoeff(DstScalar& a, const SrcScalar& b) const { a /= b; }
-  
+
   template<int Alignment, typename Packet>
   EIGEN_STRONG_INLINE void assignPacket(DstScalar* a, const Packet& b) const
   { internal::pstoret<DstScalar,Packet,Alignment>(a,internal::pdiv(internal::ploadt<Packet,Alignment>(a),b)); }
@@ -143,7 +138,6 @@ struct functor_traits<div_assign_op<DstScalar,SrcScalar> > {
   */
 template<typename Scalar> struct swap_assign_op {
 
-  EIGEN_EMPTY_STRUCT_CTOR(swap_assign_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void assignCoeff(Scalar& a, const Scalar& b) const
   {
 #ifdef EIGEN_GPUCC
diff --git a/Eigen/src/Core/functors/BinaryFunctors.h b/Eigen/src/Core/functors/BinaryFunctors.h
index 88e2e8a8a..094acb401 100644
--- a/Eigen/src/Core/functors/BinaryFunctors.h
+++ b/Eigen/src/Core/functors/BinaryFunctors.h
@@ -34,9 +34,7 @@ template<typename LhsScalar,typename RhsScalar>
 struct scalar_sum_op : binary_op_base<LhsScalar,RhsScalar>
 {
   typedef typename ScalarBinaryOpTraits<LhsScalar,RhsScalar,scalar_sum_op>::ReturnType result_type;
-#ifndef EIGEN_SCALAR_BINARY_OP_PLUGIN
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_sum_op)
-#else
+#ifdef EIGEN_SCALAR_BINARY_OP_PLUGIN
   scalar_sum_op() {
     EIGEN_SCALAR_BINARY_OP_PLUGIN
   }
@@ -72,9 +70,7 @@ template<typename LhsScalar,typename RhsScalar>
 struct scalar_product_op  : binary_op_base<LhsScalar,RhsScalar>
 {
   typedef typename ScalarBinaryOpTraits<LhsScalar,RhsScalar,scalar_product_op>::ReturnType result_type;
-#ifndef EIGEN_SCALAR_BINARY_OP_PLUGIN
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_product_op)
-#else
+#ifdef EIGEN_SCALAR_BINARY_OP_PLUGIN
   scalar_product_op() {
     EIGEN_SCALAR_BINARY_OP_PLUGIN
   }
@@ -115,7 +111,6 @@ struct scalar_conj_product_op  : binary_op_base<LhsScalar,RhsScalar>
 
   typedef typename ScalarBinaryOpTraits<LhsScalar,RhsScalar,scalar_conj_product_op>::ReturnType result_type;
 
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_conj_product_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type operator() (const LhsScalar& a, const RhsScalar& b) const
   { return conj_helper<LhsScalar,RhsScalar,Conj,false>().pmul(a,b); }
 
@@ -140,7 +135,6 @@ template<typename LhsScalar,typename RhsScalar, int NaNPropagation>
 struct scalar_min_op : binary_op_base<LhsScalar,RhsScalar>
 {
   typedef typename ScalarBinaryOpTraits<LhsScalar,RhsScalar,scalar_min_op>::ReturnType result_type;
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_min_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type operator() (const LhsScalar& a, const RhsScalar& b) const {
     return internal::pmin<NaNPropagation>(a, b);
   }
@@ -173,7 +167,6 @@ template<typename LhsScalar,typename RhsScalar, int NaNPropagation>
 struct scalar_max_op : binary_op_base<LhsScalar,RhsScalar>
 {
   typedef typename ScalarBinaryOpTraits<LhsScalar,RhsScalar,scalar_max_op>::ReturnType result_type;
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_max_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type operator() (const LhsScalar& a, const RhsScalar& b) const {
     return internal::pmax<NaNPropagation>(a,b);
   }
@@ -225,7 +218,6 @@ template<typename LhsScalar, typename RhsScalar>
 struct scalar_cmp_op<LhsScalar,RhsScalar, cmp_EQ> : binary_op_base<LhsScalar,RhsScalar>
 {
   typedef bool result_type;
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cmp_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool operator()(const LhsScalar& a, const RhsScalar& b) const {return a==b;}
   template<typename Packet>
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a, const Packet& b) const
@@ -235,7 +227,6 @@ template<typename LhsScalar, typename RhsScalar>
 struct scalar_cmp_op<LhsScalar,RhsScalar, cmp_LT> : binary_op_base<LhsScalar,RhsScalar>
 {
   typedef bool result_type;
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cmp_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool operator()(const LhsScalar& a, const RhsScalar& b) const {return a<b;}
   template<typename Packet>
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a, const Packet& b) const
@@ -245,7 +236,6 @@ template<typename LhsScalar, typename RhsScalar>
 struct scalar_cmp_op<LhsScalar,RhsScalar, cmp_LE> : binary_op_base<LhsScalar,RhsScalar>
 {
   typedef bool result_type;
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cmp_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool operator()(const LhsScalar& a, const RhsScalar& b) const {return a<=b;}
   template<typename Packet>
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a, const Packet& b) const
@@ -255,7 +245,6 @@ template<typename LhsScalar, typename RhsScalar>
 struct scalar_cmp_op<LhsScalar,RhsScalar, cmp_GT> : binary_op_base<LhsScalar,RhsScalar>
 {
   typedef bool result_type;
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cmp_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool operator()(const LhsScalar& a, const RhsScalar& b) const {return a>b;}
   template<typename Packet>
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a, const Packet& b) const
@@ -265,7 +254,6 @@ template<typename LhsScalar, typename RhsScalar>
 struct scalar_cmp_op<LhsScalar,RhsScalar, cmp_GE> : binary_op_base<LhsScalar,RhsScalar>
 {
   typedef bool result_type;
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cmp_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool operator()(const LhsScalar& a, const RhsScalar& b) const {return a>=b;}
   template<typename Packet>
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a, const Packet& b) const
@@ -275,7 +263,6 @@ template<typename LhsScalar, typename RhsScalar>
 struct scalar_cmp_op<LhsScalar,RhsScalar, cmp_UNORD> : binary_op_base<LhsScalar,RhsScalar>
 {
   typedef bool result_type;
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cmp_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool operator()(const LhsScalar& a, const RhsScalar& b) const {return !(a<=b || b<=a);}
   template<typename Packet>
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a, const Packet& b) const
@@ -285,7 +272,6 @@ template<typename LhsScalar, typename RhsScalar>
 struct scalar_cmp_op<LhsScalar,RhsScalar, cmp_NEQ> : binary_op_base<LhsScalar,RhsScalar>
 {
   typedef bool result_type;
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cmp_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool operator()(const LhsScalar& a, const RhsScalar& b) const {return a!=b;}
   template<typename Packet>
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a, const Packet& b) const
@@ -300,8 +286,6 @@ struct scalar_cmp_op<LhsScalar,RhsScalar, cmp_NEQ> : binary_op_base<LhsScalar,Rh
 template<typename Scalar>
 struct scalar_hypot_op<Scalar,Scalar> : binary_op_base<Scalar,Scalar>
 {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_hypot_op)
-
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar &x, const Scalar &y) const
   {
     // This functor is used by hypotNorm only for which it is faster to first apply abs
@@ -331,9 +315,7 @@ template<typename Scalar, typename Exponent>
 struct scalar_pow_op  : binary_op_base<Scalar,Exponent>
 {
   typedef typename ScalarBinaryOpTraits<Scalar,Exponent,scalar_pow_op>::ReturnType result_type;
-#ifndef EIGEN_SCALAR_BINARY_OP_PLUGIN
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_pow_op)
-#else
+#ifdef EIGEN_SCALAR_BINARY_OP_PLUGIN
   scalar_pow_op() {
     typedef Scalar LhsScalar;
     typedef Exponent RhsScalar;
@@ -376,9 +358,7 @@ template<typename LhsScalar,typename RhsScalar>
 struct scalar_difference_op : binary_op_base<LhsScalar,RhsScalar>
 {
   typedef typename ScalarBinaryOpTraits<LhsScalar,RhsScalar,scalar_difference_op>::ReturnType result_type;
-#ifndef EIGEN_SCALAR_BINARY_OP_PLUGIN
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_difference_op)
-#else
+#ifdef EIGEN_SCALAR_BINARY_OP_PLUGIN
   scalar_difference_op() {
     EIGEN_SCALAR_BINARY_OP_PLUGIN
   }
@@ -405,9 +385,7 @@ template<typename LhsScalar,typename RhsScalar>
 struct scalar_quotient_op  : binary_op_base<LhsScalar,RhsScalar>
 {
   typedef typename ScalarBinaryOpTraits<LhsScalar,RhsScalar,scalar_quotient_op>::ReturnType result_type;
-#ifndef EIGEN_SCALAR_BINARY_OP_PLUGIN
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_quotient_op)
-#else
+#ifdef EIGEN_SCALAR_BINARY_OP_PLUGIN
   scalar_quotient_op() {
     EIGEN_SCALAR_BINARY_OP_PLUGIN
   }
@@ -434,7 +412,6 @@ struct functor_traits<scalar_quotient_op<LhsScalar,RhsScalar> > {
   * \sa class CwiseBinaryOp, ArrayBase::operator&&
   */
 struct scalar_boolean_and_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_boolean_and_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool operator() (const bool& a, const bool& b) const { return a && b; }
   template<typename Packet>
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a, const Packet& b) const
@@ -453,7 +430,6 @@ template<> struct functor_traits<scalar_boolean_and_op> {
   * \sa class CwiseBinaryOp, ArrayBase::operator||
   */
 struct scalar_boolean_or_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_boolean_or_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool operator() (const bool& a, const bool& b) const { return a || b; }
   template<typename Packet>
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a, const Packet& b) const
@@ -472,7 +448,6 @@ template<> struct functor_traits<scalar_boolean_or_op> {
  * \sa class CwiseBinaryOp, ArrayBase::operator^
  */
 struct scalar_boolean_xor_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_boolean_xor_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool operator() (const bool& a, const bool& b) const { return a ^ b; }
   template<typename Packet>
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a, const Packet& b) const
@@ -494,9 +469,7 @@ template<typename LhsScalar,typename RhsScalar>
 struct scalar_absolute_difference_op : binary_op_base<LhsScalar,RhsScalar>
 {
   typedef typename ScalarBinaryOpTraits<LhsScalar,RhsScalar,scalar_absolute_difference_op>::ReturnType result_type;
-#ifndef EIGEN_SCALAR_BINARY_OP_PLUGIN
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_absolute_difference_op)
-#else
+#ifdef EIGEN_SCALAR_BINARY_OP_PLUGIN
   scalar_absolute_difference_op() {
     EIGEN_SCALAR_BINARY_OP_PLUGIN
   }
diff --git a/Eigen/src/Core/functors/NullaryFunctors.h b/Eigen/src/Core/functors/NullaryFunctors.h
index 0293a9957..e099d4ac1 100644
--- a/Eigen/src/Core/functors/NullaryFunctors.h
+++ b/Eigen/src/Core/functors/NullaryFunctors.h
@@ -31,7 +31,6 @@ struct functor_traits<scalar_constant_op<Scalar> >
          PacketAccess = packet_traits<Scalar>::Vectorizable, IsRepeatable = true }; };
 
 template<typename Scalar> struct scalar_identity_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_identity_op)
   template<typename IndexType>
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (IndexType row, IndexType col) const { return row==col ? Scalar(1) : Scalar(0); }
 };
diff --git a/Eigen/src/Core/functors/UnaryFunctors.h b/Eigen/src/Core/functors/UnaryFunctors.h
index e7bccafe0..fafb53376 100644
--- a/Eigen/src/Core/functors/UnaryFunctors.h
+++ b/Eigen/src/Core/functors/UnaryFunctors.h
@@ -22,7 +22,6 @@ namespace internal {
   * \sa class CwiseUnaryOp, MatrixBase::operator-
   */
 template<typename Scalar> struct scalar_opposite_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_opposite_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a) const { return -a; }
   template<typename Packet>
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const
@@ -41,7 +40,6 @@ struct functor_traits<scalar_opposite_op<Scalar> >
   * \sa class CwiseUnaryOp, Cwise::abs
   */
 template<typename Scalar> struct scalar_abs_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_abs_op)
   typedef typename NumTraits<Scalar>::Real result_type;
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const result_type operator() (const Scalar& a) const { return numext::abs(a); }
   template<typename Packet>
@@ -72,14 +70,12 @@ struct functor_traits<scalar_score_coeff_op<Scalar> > : functor_traits<scalar_ab
 /* Avoid recomputing abs when we know the score and they are the same. Not a true Eigen functor.  */
 template<typename Scalar, typename=void> struct abs_knowing_score
 {
-  EIGEN_EMPTY_STRUCT_CTOR(abs_knowing_score)
   typedef typename NumTraits<Scalar>::Real result_type;
   template<typename Score>
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const result_type operator() (const Scalar& a, const Score&) const { return numext::abs(a); }
 };
 template<typename Scalar> struct abs_knowing_score<Scalar, typename scalar_score_coeff_op<Scalar>::Score_is_abs>
 {
-  EIGEN_EMPTY_STRUCT_CTOR(abs_knowing_score)
   typedef typename NumTraits<Scalar>::Real result_type;
   template<typename Scal>
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const result_type operator() (const Scal&, const result_type& a) const { return a; }
@@ -91,7 +87,6 @@ template<typename Scalar> struct abs_knowing_score<Scalar, typename scalar_score
   * \sa class CwiseUnaryOp, Cwise::abs2
   */
 template<typename Scalar> struct scalar_abs2_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_abs2_op)
   typedef typename NumTraits<Scalar>::Real result_type;
   EIGEN_DEVICE_FUNC
   EIGEN_STRONG_INLINE const result_type operator() (const Scalar& a) const { return numext::abs2(a); }
@@ -109,7 +104,6 @@ struct functor_traits<scalar_abs2_op<Scalar> >
   * \sa class CwiseUnaryOp, MatrixBase::conjugate()
   */
 template<typename Scalar> struct scalar_conjugate_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_conjugate_op)
   EIGEN_DEVICE_FUNC
   EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a) const { return numext::conj(a); }
   template<typename Packet>
@@ -138,7 +132,6 @@ struct functor_traits<scalar_conjugate_op<Scalar> >
   * \sa class CwiseUnaryOp, Cwise::arg
   */
 template<typename Scalar> struct scalar_arg_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_arg_op)
   typedef typename NumTraits<Scalar>::Real result_type;
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const result_type operator() (const Scalar& a) const { return numext::arg(a); }
   template<typename Packet>
@@ -160,7 +153,6 @@ struct functor_traits<scalar_arg_op<Scalar> >
   */
 template<typename Scalar, typename NewType>
 struct scalar_cast_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cast_op)
   typedef NewType result_type;
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const NewType operator() (const Scalar& a) const { return cast<Scalar, NewType>(a); }
 };
@@ -175,7 +167,6 @@ struct functor_traits<scalar_cast_op<Scalar,NewType> >
   */
 template<typename Scalar, int N>
 struct scalar_shift_right_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_shift_right_op)
 
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a) const
   { return a >> N; }
@@ -194,8 +185,6 @@ struct functor_traits<scalar_shift_right_op<Scalar,N> >
   */
 template<typename Scalar, int N>
 struct scalar_shift_left_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_shift_left_op)
-
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a) const
   { return a << N; }
   template<typename Packet>
@@ -213,7 +202,6 @@ struct functor_traits<scalar_shift_left_op<Scalar,N> >
   */
 template<typename Scalar>
 struct scalar_real_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_real_op)
   typedef typename NumTraits<Scalar>::Real result_type;
   EIGEN_DEVICE_FUNC
   EIGEN_STRONG_INLINE result_type operator() (const Scalar& a) const { return numext::real(a); }
@@ -229,7 +217,6 @@ struct functor_traits<scalar_real_op<Scalar> >
   */
 template<typename Scalar>
 struct scalar_imag_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_imag_op)
   typedef typename NumTraits<Scalar>::Real result_type;
   EIGEN_DEVICE_FUNC
   EIGEN_STRONG_INLINE result_type operator() (const Scalar& a) const { return numext::imag(a); }
@@ -245,7 +232,6 @@ struct functor_traits<scalar_imag_op<Scalar> >
   */
 template<typename Scalar>
 struct scalar_real_ref_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_real_ref_op)
   typedef typename NumTraits<Scalar>::Real result_type;
   EIGEN_DEVICE_FUNC
   EIGEN_STRONG_INLINE result_type& operator() (const Scalar& a) const { return numext::real_ref(*const_cast<Scalar*>(&a)); }
@@ -261,7 +247,6 @@ struct functor_traits<scalar_real_ref_op<Scalar> >
   */
 template<typename Scalar>
 struct scalar_imag_ref_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_imag_ref_op)
   typedef typename NumTraits<Scalar>::Real result_type;
   EIGEN_DEVICE_FUNC
   EIGEN_STRONG_INLINE result_type& operator() (const Scalar& a) const { return numext::imag_ref(*const_cast<Scalar*>(&a)); }
@@ -277,7 +262,6 @@ struct functor_traits<scalar_imag_ref_op<Scalar> >
   * \sa class CwiseUnaryOp, Cwise::exp()
   */
 template<typename Scalar> struct scalar_exp_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_exp_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const { return internal::pexp(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::pexp(a); }
@@ -317,7 +301,6 @@ struct functor_traits<scalar_exp_op<Scalar> > {
   * \sa class CwiseUnaryOp, ArrayBase::expm1()
   */
 template<typename Scalar> struct scalar_expm1_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_expm1_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const { return numext::expm1(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::pexpm1(a); }
@@ -337,7 +320,6 @@ struct functor_traits<scalar_expm1_op<Scalar> > {
   * \sa class CwiseUnaryOp, ArrayBase::log()
   */
 template<typename Scalar> struct scalar_log_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_log_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const { return numext::log(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::plog(a); }
@@ -368,7 +350,6 @@ struct functor_traits<scalar_log_op<Scalar> > {
   * \sa class CwiseUnaryOp, ArrayBase::log1p()
   */
 template<typename Scalar> struct scalar_log1p_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_log1p_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const { return numext::log1p(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::plog1p(a); }
@@ -388,7 +369,6 @@ struct functor_traits<scalar_log1p_op<Scalar> > {
   * \sa class CwiseUnaryOp, Cwise::log10()
   */
 template<typename Scalar> struct scalar_log10_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_log10_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const { EIGEN_USING_STD(log10) return log10(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::plog10(a); }
@@ -404,7 +384,6 @@ struct functor_traits<scalar_log10_op<Scalar> >
   * \sa class CwiseUnaryOp, Cwise::log2()
   */
 template<typename Scalar> struct scalar_log2_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_log2_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const { return Scalar(EIGEN_LOG2E) * numext::log(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::plog2(a); }
@@ -418,7 +397,6 @@ struct functor_traits<scalar_log2_op<Scalar> >
   * \sa class CwiseUnaryOp, Cwise::sqrt()
   */
 template<typename Scalar> struct scalar_sqrt_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_sqrt_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const { return numext::sqrt(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::psqrt(a); }
@@ -442,7 +420,6 @@ struct functor_traits<scalar_sqrt_op<Scalar> > {
 
 // Boolean specialization to eliminate -Wimplicit-conversion-floating-point-to-bool warnings.
 template<> struct scalar_sqrt_op<bool> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_sqrt_op)
   EIGEN_DEPRECATED EIGEN_DEVICE_FUNC inline bool operator() (const bool& a) const { return a; }
   template <typename Packet>
   EIGEN_DEPRECATED EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return a; }
@@ -457,7 +434,6 @@ struct functor_traits<scalar_sqrt_op<bool> > {
   * \sa class CwiseUnaryOp, Cwise::rsqrt()
   */
 template<typename Scalar> struct scalar_rsqrt_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_rsqrt_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const { return numext::rsqrt(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::prsqrt(a); }
@@ -476,7 +452,6 @@ struct functor_traits<scalar_rsqrt_op<Scalar> >
   * \sa class CwiseUnaryOp, ArrayBase::cos()
   */
 template<typename Scalar> struct scalar_cos_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cos_op)
   EIGEN_DEVICE_FUNC inline Scalar operator() (const Scalar& a) const { return numext::cos(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::pcos(a); }
@@ -495,7 +470,6 @@ struct functor_traits<scalar_cos_op<Scalar> >
   * \sa class CwiseUnaryOp, ArrayBase::sin()
   */
 template<typename Scalar> struct scalar_sin_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_sin_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const { return numext::sin(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::psin(a); }
@@ -515,7 +489,6 @@ struct functor_traits<scalar_sin_op<Scalar> >
   * \sa class CwiseUnaryOp, ArrayBase::tan()
   */
 template<typename Scalar> struct scalar_tan_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_tan_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const { return numext::tan(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::ptan(a); }
@@ -534,7 +507,6 @@ struct functor_traits<scalar_tan_op<Scalar> >
   * \sa class CwiseUnaryOp, ArrayBase::acos()
   */
 template<typename Scalar> struct scalar_acos_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_acos_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const { return numext::acos(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::pacos(a); }
@@ -553,7 +525,6 @@ struct functor_traits<scalar_acos_op<Scalar> >
   * \sa class CwiseUnaryOp, ArrayBase::asin()
   */
 template<typename Scalar> struct scalar_asin_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_asin_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const { return numext::asin(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::pasin(a); }
@@ -573,7 +544,6 @@ struct functor_traits<scalar_asin_op<Scalar> >
   * \sa class CwiseUnaryOp, ArrayBase::atan()
   */
 template<typename Scalar> struct scalar_atan_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_atan_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const { return numext::atan(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::patan(a); }
@@ -593,7 +563,6 @@ struct functor_traits<scalar_atan_op<Scalar> >
   */
 template <typename Scalar>
 struct scalar_tanh_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_tanh_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::tanh(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& x) const { return ptanh(x); }
@@ -631,7 +600,6 @@ struct functor_traits<scalar_tanh_op<Scalar> > {
   */
 template <typename Scalar>
 struct scalar_atanh_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_atanh_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::atanh(a); }
 };
 
@@ -646,7 +614,6 @@ struct functor_traits<scalar_atanh_op<Scalar> > {
   * \sa class CwiseUnaryOp, ArrayBase::sinh()
   */
 template<typename Scalar> struct scalar_sinh_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_sinh_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const { return numext::sinh(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::psinh(a); }
@@ -667,7 +634,6 @@ struct functor_traits<scalar_sinh_op<Scalar> >
   */
 template <typename Scalar>
 struct scalar_asinh_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_asinh_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::asinh(a); }
 };
 
@@ -682,7 +648,6 @@ struct functor_traits<scalar_asinh_op<Scalar> > {
   * \sa class CwiseUnaryOp, ArrayBase::cosh()
   */
 template<typename Scalar> struct scalar_cosh_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cosh_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const { return numext::cosh(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::pcosh(a); }
@@ -703,7 +668,6 @@ struct functor_traits<scalar_cosh_op<Scalar> >
   */
 template <typename Scalar>
 struct scalar_acosh_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_acosh_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::acosh(a); }
 };
 
@@ -719,7 +683,6 @@ struct functor_traits<scalar_acosh_op<Scalar> > {
   */
 template<typename Scalar>
 struct scalar_inverse_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_inverse_op)
   EIGEN_DEVICE_FUNC inline Scalar operator() (const Scalar& a) const { return Scalar(1)/a; }
   template<typename Packet>
   EIGEN_DEVICE_FUNC inline const Packet packetOp(const Packet& a) const
@@ -744,7 +707,6 @@ struct functor_traits<scalar_inverse_op<Scalar> > {
   */
 template<typename Scalar>
 struct scalar_square_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_square_op)
   EIGEN_DEVICE_FUNC inline Scalar operator() (const Scalar& a) const { return a*a; }
   template<typename Packet>
   EIGEN_DEVICE_FUNC inline const Packet packetOp(const Packet& a) const
@@ -757,7 +719,6 @@ struct functor_traits<scalar_square_op<Scalar> >
 // Boolean specialization to avoid -Wint-in-bool-context warnings on GCC.
 template<>
 struct scalar_square_op<bool> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_square_op)
   EIGEN_DEPRECATED EIGEN_DEVICE_FUNC inline bool operator() (const bool& a) const { return a; }
   template<typename Packet>
   EIGEN_DEPRECATED EIGEN_DEVICE_FUNC inline const Packet packetOp(const Packet& a) const
@@ -773,7 +734,6 @@ struct functor_traits<scalar_square_op<bool> >
   */
 template<typename Scalar>
 struct scalar_cube_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cube_op)
   EIGEN_DEVICE_FUNC inline Scalar operator() (const Scalar& a) const { return a*a*a; }
   template<typename Packet>
   EIGEN_DEVICE_FUNC inline const Packet packetOp(const Packet& a) const
@@ -786,7 +746,6 @@ struct functor_traits<scalar_cube_op<Scalar> >
 // Boolean specialization to avoid -Wint-in-bool-context warnings on GCC.
 template<>
 struct scalar_cube_op<bool> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cube_op)
   EIGEN_DEPRECATED EIGEN_DEVICE_FUNC inline bool operator() (const bool& a) const { return a; }
   template<typename Packet>
   EIGEN_DEPRECATED EIGEN_DEVICE_FUNC inline const Packet packetOp(const Packet& a) const
@@ -801,7 +760,6 @@ struct functor_traits<scalar_cube_op<bool> >
   * \sa class CwiseUnaryOp, ArrayBase::round()
   */
 template<typename Scalar> struct scalar_round_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_round_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a) const { return numext::round(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::pround(a); }
@@ -820,7 +778,6 @@ struct functor_traits<scalar_round_op<Scalar> >
   * \sa class CwiseUnaryOp, ArrayBase::floor()
   */
 template<typename Scalar> struct scalar_floor_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_floor_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a) const { return numext::floor(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::pfloor(a); }
@@ -839,7 +796,6 @@ struct functor_traits<scalar_floor_op<Scalar> >
   * \sa class CwiseUnaryOp, ArrayBase::rint()
   */
 template<typename Scalar> struct scalar_rint_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_rint_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a) const { return numext::rint(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::print(a); }
@@ -858,7 +814,6 @@ struct functor_traits<scalar_rint_op<Scalar> >
   * \sa class CwiseUnaryOp, ArrayBase::ceil()
   */
 template<typename Scalar> struct scalar_ceil_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_ceil_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a) const { return numext::ceil(a); }
   template <typename Packet>
   EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const { return internal::pceil(a); }
@@ -877,7 +832,6 @@ struct functor_traits<scalar_ceil_op<Scalar> >
   * \sa class CwiseUnaryOp, ArrayBase::isnan()
   */
 template<typename Scalar> struct scalar_isnan_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_isnan_op)
   typedef bool result_type;
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type operator() (const Scalar& a) const {
 #if defined(SYCL_DEVICE_ONLY)
@@ -901,7 +855,6 @@ struct functor_traits<scalar_isnan_op<Scalar> >
   * \sa class CwiseUnaryOp, ArrayBase::isinf()
   */
 template<typename Scalar> struct scalar_isinf_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_isinf_op)
   typedef bool result_type;
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type operator() (const Scalar& a) const {
 #if defined(SYCL_DEVICE_ONLY)
@@ -925,7 +878,6 @@ struct functor_traits<scalar_isinf_op<Scalar> >
   * \sa class CwiseUnaryOp, ArrayBase::isfinite()
   */
 template<typename Scalar> struct scalar_isfinite_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_isfinite_op)
   typedef bool result_type;
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type operator() (const Scalar& a) const {
 #if defined(SYCL_DEVICE_ONLY)
@@ -950,7 +902,6 @@ struct functor_traits<scalar_isfinite_op<Scalar> >
   * \sa class CwiseUnaryOp, ArrayBase::operator!
   */
 template<typename Scalar> struct scalar_boolean_not_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_boolean_not_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool operator() (const bool& a) const { return !a; }
 };
 template<typename Scalar>
@@ -968,7 +919,6 @@ struct functor_traits<scalar_boolean_not_op<Scalar> > {
 template<typename Scalar,bool is_complex=(NumTraits<Scalar>::IsComplex!=0), bool is_integer=(NumTraits<Scalar>::IsInteger!=0) > struct scalar_sign_op;
 template<typename Scalar>
 struct scalar_sign_op<Scalar, false, true> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_sign_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const
   {
       return Scalar( (a>Scalar(0)) - (a<Scalar(0)) );
@@ -980,7 +930,6 @@ struct scalar_sign_op<Scalar, false, true> {
 
 template<typename Scalar>
 struct scalar_sign_op<Scalar, false, false> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_sign_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const
   {
     return (numext::isnan)(a) ? a : Scalar( (a>Scalar(0)) - (a<Scalar(0)) );
@@ -992,7 +941,6 @@ struct scalar_sign_op<Scalar, false, false> {
 
 template<typename Scalar, bool is_integer>
 struct scalar_sign_op<Scalar,true, is_integer> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_sign_op)
   EIGEN_DEVICE_FUNC inline const Scalar operator() (const Scalar& a) const
   {
     typedef typename NumTraits<Scalar>::Real real_type;
@@ -1023,7 +971,6 @@ struct functor_traits<scalar_sign_op<Scalar> >
   */
 template <typename T>
 struct scalar_logistic_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_logistic_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE T operator()(const T& x) const {
     return packetOp(x);
   }
@@ -1059,7 +1006,6 @@ struct scalar_logistic_op {
   */
 template <>
 struct scalar_logistic_op<float> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_logistic_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE float operator()(const float& x) const {
     // Truncate at the first point where the interpolant is exactly one.
     const float cst_exp_hi = 16.6355324f;
diff --git a/Eigen/src/Core/util/XprHelper.h b/Eigen/src/Core/util/XprHelper.h
index 5823f029f..ba8a7f1cb 100644
--- a/Eigen/src/Core/util/XprHelper.h
+++ b/Eigen/src/Core/util/XprHelper.h
@@ -11,17 +11,6 @@
 #ifndef EIGEN_XPRHELPER_H
 #define EIGEN_XPRHELPER_H
 
-// just a workaround because GCC seems to not really like empty structs
-// FIXME: gcc 4.3 generates bad code when strict-aliasing is enabled
-// so currently we simply disable this optimization for gcc 4.3
-#if EIGEN_COMP_GNUC
-  #define EIGEN_EMPTY_STRUCT_CTOR(X) \
-    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE X() {} \
-    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE X(const X& ) {}
-#else
-  #define EIGEN_EMPTY_STRUCT_CTOR(X)
-#endif
-
 #include "../InternalHeaderCheck.h"
 
 namespace Eigen {
@@ -148,7 +137,6 @@ template<typename T> class variable_if_dynamic<T, Dynamic>
 template<typename T, int Value> class variable_if_dynamicindex
 {
   public:
-    EIGEN_EMPTY_STRUCT_CTOR(variable_if_dynamicindex)
     EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE explicit variable_if_dynamicindex(T v) { EIGEN_ONLY_USED_FOR_DEBUG(v); eigen_assert(v == T(Value)); }
     EIGEN_DEVICE_FUNC static EIGEN_STRONG_INLINE EIGEN_CONSTEXPR
     T value() { return T(Value); }
diff --git a/blas/level1_cplx_impl.h b/blas/level1_cplx_impl.h
index 6c7edd7eb..aa4678442 100644
--- a/blas/level1_cplx_impl.h
+++ b/blas/level1_cplx_impl.h
@@ -11,7 +11,6 @@
 
 struct scalar_norm1_op {
   typedef RealScalar result_type;
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_norm1_op)
   inline RealScalar operator() (const Scalar& a) const { return numext::norm1(a); }
 };
 namespace Eigen {
diff --git a/doc/examples/class_CwiseBinaryOp.cpp b/doc/examples/class_CwiseBinaryOp.cpp
index aec926dce..973befdee 100644
--- a/doc/examples/class_CwiseBinaryOp.cpp
+++ b/doc/examples/class_CwiseBinaryOp.cpp
@@ -5,7 +5,6 @@ using Eigen::Matrix4d;
 
 // define a custom template binary functor
 template<typename Scalar> struct MakeComplexOp {
-  EIGEN_EMPTY_STRUCT_CTOR(MakeComplexOp)
   typedef std::complex<Scalar> result_type;
   result_type operator()(const Scalar& a, const Scalar& b) const { return result_type(a,b); }
 };
diff --git a/test/unaryviewstride.cpp b/test/unaryviewstride.cpp
index 08d097fb6..03a770b5c 100644
--- a/test/unaryviewstride.cpp
+++ b/test/unaryviewstride.cpp
@@ -17,9 +17,8 @@ template<int OuterStride,int InnerStride,typename VectorType> void unaryview_str
   VectorType vec = VectorType::Random(rows, cols);
 
   struct view_op {
-    EIGEN_EMPTY_STRUCT_CTOR(view_op)
     EIGEN_DEVICE_FUNC
-    EIGEN_STRONG_INLINE const Scalar& 
+    EIGEN_STRONG_INLINE const Scalar&
       operator()(const Scalar& v) const { return v; }
   };
 
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorFunctors.h b/unsupported/Eigen/CXX11/src/Tensor/TensorFunctors.h
index 780451f1d..137fe5878 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorFunctors.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorFunctors.h
@@ -35,7 +35,6 @@ struct functor_traits<scalar_mod_op<Scalar> >
  */
 template <typename Scalar>
 struct scalar_mod2_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_mod2_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator() (const Scalar& a, const Scalar& b) const { return a % b; }
 };
 template <typename Scalar>
@@ -44,7 +43,6 @@ struct functor_traits<scalar_mod2_op<Scalar> >
 
 template <typename Scalar>
 struct scalar_fmod_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_fmod_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar
   operator()(const Scalar& a, const Scalar& b) const {
     return numext::fmod(a, b);
diff --git a/unsupported/Eigen/src/SpecialFunctions/BesselFunctionsFunctors.h b/unsupported/Eigen/src/SpecialFunctions/BesselFunctionsFunctors.h
index 623f0b99d..2d6b386ee 100644
--- a/unsupported/Eigen/src/SpecialFunctions/BesselFunctionsFunctors.h
+++ b/unsupported/Eigen/src/SpecialFunctions/BesselFunctionsFunctors.h
@@ -24,7 +24,6 @@ namespace internal {
  */
 template <typename Scalar>
 struct scalar_bessel_i0_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_bessel_i0_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& x) const {
     using numext::bessel_i0;
     return bessel_i0(x);
@@ -52,7 +51,6 @@ struct functor_traits<scalar_bessel_i0_op<Scalar> > {
  */
 template <typename Scalar>
 struct scalar_bessel_i0e_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_bessel_i0e_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& x) const {
     using numext::bessel_i0e;
     return bessel_i0e(x);
@@ -79,7 +77,6 @@ struct functor_traits<scalar_bessel_i0e_op<Scalar> > {
  */
 template <typename Scalar>
 struct scalar_bessel_i1_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_bessel_i1_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& x) const {
     using numext::bessel_i1;
     return bessel_i1(x);
@@ -107,7 +104,6 @@ struct functor_traits<scalar_bessel_i1_op<Scalar> > {
  */
 template <typename Scalar>
 struct scalar_bessel_i1e_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_bessel_i1e_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& x) const {
     using numext::bessel_i1e;
     return bessel_i1e(x);
@@ -134,7 +130,6 @@ struct functor_traits<scalar_bessel_i1e_op<Scalar> > {
  */
 template <typename Scalar>
 struct scalar_bessel_j0_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_bessel_j0_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& x) const {
     using numext::bessel_j0;
     return bessel_j0(x);
@@ -162,7 +157,6 @@ struct functor_traits<scalar_bessel_j0_op<Scalar> > {
  */
 template <typename Scalar>
 struct scalar_bessel_y0_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_bessel_y0_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& x) const {
     using numext::bessel_y0;
     return bessel_y0(x);
@@ -190,7 +184,6 @@ struct functor_traits<scalar_bessel_y0_op<Scalar> > {
  */
 template <typename Scalar>
 struct scalar_bessel_j1_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_bessel_j1_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& x) const {
     using numext::bessel_j1;
     return bessel_j1(x);
@@ -218,7 +211,6 @@ struct functor_traits<scalar_bessel_j1_op<Scalar> > {
  */
 template <typename Scalar>
 struct scalar_bessel_y1_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_bessel_y1_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& x) const {
     using numext::bessel_y1;
     return bessel_y1(x);
@@ -246,7 +238,6 @@ struct functor_traits<scalar_bessel_y1_op<Scalar> > {
  */
 template <typename Scalar>
 struct scalar_bessel_k0_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_bessel_k0_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& x) const {
     using numext::bessel_k0;
     return bessel_k0(x);
@@ -274,7 +265,6 @@ struct functor_traits<scalar_bessel_k0_op<Scalar> > {
  */
 template <typename Scalar>
 struct scalar_bessel_k0e_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_bessel_k0e_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& x) const {
     using numext::bessel_k0e;
     return bessel_k0e(x);
@@ -302,7 +292,6 @@ struct functor_traits<scalar_bessel_k0e_op<Scalar> > {
  */
 template <typename Scalar>
 struct scalar_bessel_k1_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_bessel_k1_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& x) const {
     using numext::bessel_k1;
     return bessel_k1(x);
@@ -330,7 +319,6 @@ struct functor_traits<scalar_bessel_k1_op<Scalar> > {
  */
 template <typename Scalar>
 struct scalar_bessel_k1e_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_bessel_k1e_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& x) const {
     using numext::bessel_k1e;
     return bessel_k1e(x);
diff --git a/unsupported/Eigen/src/SpecialFunctions/SpecialFunctionsFunctors.h b/unsupported/Eigen/src/SpecialFunctions/SpecialFunctionsFunctors.h
index 125f1b907..0955c436d 100644
--- a/unsupported/Eigen/src/SpecialFunctions/SpecialFunctionsFunctors.h
+++ b/unsupported/Eigen/src/SpecialFunctions/SpecialFunctionsFunctors.h
@@ -25,7 +25,6 @@ namespace internal {
   */
 template<typename Scalar> struct scalar_igamma_op : binary_op_base<Scalar,Scalar>
 {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_igamma_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a, const Scalar& x) const {
     using numext::igamma; return igamma(a, x);
   }
@@ -51,7 +50,6 @@ struct functor_traits<scalar_igamma_op<Scalar> > {
   */
 template <typename Scalar>
 struct scalar_igamma_der_a_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_igamma_der_a_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& a, const Scalar& x) const {
     using numext::igamma_der_a;
     return igamma_der_a(a, x);
@@ -79,7 +77,6 @@ struct functor_traits<scalar_igamma_der_a_op<Scalar> > {
   */
 template <typename Scalar>
 struct scalar_gamma_sample_der_alpha_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_gamma_sample_der_alpha_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& alpha, const Scalar& sample) const {
     using numext::gamma_sample_der_alpha;
     return gamma_sample_der_alpha(alpha, sample);
@@ -105,7 +102,6 @@ struct functor_traits<scalar_gamma_sample_der_alpha_op<Scalar> > {
   */
 template<typename Scalar> struct scalar_igammac_op : binary_op_base<Scalar,Scalar>
 {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_igammac_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a, const Scalar& x) const {
     using numext::igammac; return igammac(a, x);
   }
@@ -130,7 +126,6 @@ struct functor_traits<scalar_igammac_op<Scalar> > {
   *
   */
 template<typename Scalar> struct scalar_betainc_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_betainc_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& x, const Scalar& a, const Scalar& b) const {
     using numext::betainc; return betainc(x, a, b);
   }
@@ -156,7 +151,6 @@ struct functor_traits<scalar_betainc_op<Scalar> > {
  * \sa class CwiseUnaryOp, Cwise::lgamma()
  */
 template<typename Scalar> struct scalar_lgamma_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_lgamma_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a) const {
     using numext::lgamma; return lgamma(a);
   }
@@ -178,7 +172,6 @@ struct functor_traits<scalar_lgamma_op<Scalar> >
  * \sa class CwiseUnaryOp, Cwise::digamma()
  */
 template<typename Scalar> struct scalar_digamma_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_digamma_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a) const {
     using numext::digamma; return digamma(a);
   }
@@ -200,7 +193,6 @@ struct functor_traits<scalar_digamma_op<Scalar> >
  * \sa class CwiseUnaryOp, Cwise::zeta()
  */
 template<typename Scalar> struct scalar_zeta_op {
-    EIGEN_EMPTY_STRUCT_CTOR(scalar_zeta_op)
     EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& x, const Scalar& q) const {
         using numext::zeta; return zeta(x, q);
     }
@@ -222,7 +214,6 @@ struct functor_traits<scalar_zeta_op<Scalar> >
  * \sa class CwiseUnaryOp, Cwise::polygamma()
  */
 template<typename Scalar> struct scalar_polygamma_op {
-    EIGEN_EMPTY_STRUCT_CTOR(scalar_polygamma_op)
     EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& n, const Scalar& x) const {
         using numext::polygamma; return polygamma(n, x);
     }
@@ -244,7 +235,6 @@ struct functor_traits<scalar_polygamma_op<Scalar> >
  * \sa class CwiseUnaryOp, ArrayBase::erf()
  */
 template<typename Scalar> struct scalar_erf_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_erf_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar
   operator()(const Scalar& a) const {
     return numext::erf(a);
@@ -283,7 +273,6 @@ struct functor_traits<scalar_erf_op<Scalar> > {
  * \sa class CwiseUnaryOp, Cwise::erfc()
  */
 template<typename Scalar> struct scalar_erfc_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_erfc_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a) const {
     using numext::erfc; return erfc(a);
   }
@@ -306,7 +295,6 @@ struct functor_traits<scalar_erfc_op<Scalar> >
  * \sa class CwiseUnaryOp, Cwise::ndtri()
  */
 template<typename Scalar> struct scalar_ndtri_op {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_ndtri_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a) const {
     using numext::ndtri; return ndtri(a);
   }