unfuck v.cwise()*w where v is real and w is complex

Eigen/src/Core/Cwise.h

@@ -31,6 +31,18 @@
 #define EIGEN_CWISE_BINOP_RETURN_TYPE(OP) \
     CwiseBinaryOp<OP<typename ei_traits<ExpressionType>::Scalar>, ExpressionType, OtherDerived>
 
+#define EIGEN_CWISE_PRODUCT_RETURN_TYPE \
+    CwiseBinaryOp< \
+      ei_scalar_product_op< \
+        typename ei_scalar_product_traits< \
+          typename ei_traits<ExpressionType>::Scalar, \
+          typename ei_traits<OtherDerived>::Scalar \
+        >::ReturnType \
+      >, \
+      ExpressionType, \
+      OtherDerived \
+    >
+
 /** \internal
   * convenient macro to defined the return type of a cwise unary operation */
 #define EIGEN_CWISE_UNOP_RETURN_TYPE(OP) \
@@ -74,7 +86,7 @@ template<typename ExpressionType> class Cwise
     inline const ExpressionType& _expression() const { return m_matrix; }
 
     template<typename OtherDerived>
-    const EIGEN_CWISE_BINOP_RETURN_TYPE(ei_scalar_product_op)
+    const EIGEN_CWISE_PRODUCT_RETURN_TYPE
     operator*(const MatrixBase<OtherDerived> &other) const;
 
     template<typename OtherDerived>

Eigen/src/Core/CwiseBinaryOp.h

@@ -54,7 +54,6 @@ struct ei_traits<CwiseBinaryOp<BinaryOp, Lhs, Rhs> >
                        typename Rhs::Scalar
                      )
                    >::type Scalar;
-
   typedef typename Lhs::Nested LhsNested;
   typedef typename Rhs::Nested RhsNested;
   typedef typename ei_unref<LhsNested>::type _LhsNested;
@@ -99,7 +98,9 @@ class CwiseBinaryOp : ei_no_assignment_operator,
       // It is tempting to always allow mixing different types but remember that this is often impossible in the vectorized paths.
       // So allowing mixing different types gives very unexpected errors when enabling vectorization, when the user tries to
       // add together a float matrix and a double matrix.
-      EIGEN_STATIC_ASSERT((ei_is_same_type<typename Lhs::Scalar, typename Rhs::Scalar>::ret),
+      EIGEN_STATIC_ASSERT((ei_functor_allows_mixing_real_and_complex<BinaryOp>::ret
+                           ? int(ei_is_same_type<typename Lhs::RealScalar, typename Rhs::RealScalar>::ret)
+                           : int(ei_is_same_type<typename Lhs::Scalar, typename Rhs::Scalar>::ret)),
         YOU_MIXED_DIFFERENT_NUMERIC_TYPES__YOU_NEED_TO_USE_THE_CAST_METHOD_OF_MATRIXBASE_TO_CAST_NUMERIC_TYPES_EXPLICITLY)
       // require the sizes to match
       EIGEN_STATIC_ASSERT_SAME_MATRIX_SIZE(Lhs, Rhs)
@@ -202,10 +203,10 @@ MatrixBase<Derived>::operator+=(const MatrixBase<OtherDerived>& other)
   */
 template<typename ExpressionType>
 template<typename OtherDerived>
-EIGEN_STRONG_INLINE const EIGEN_CWISE_BINOP_RETURN_TYPE(ei_scalar_product_op)
+EIGEN_STRONG_INLINE const EIGEN_CWISE_PRODUCT_RETURN_TYPE
 Cwise<ExpressionType>::operator*(const MatrixBase<OtherDerived> &other) const
 {
-  return EIGEN_CWISE_BINOP_RETURN_TYPE(ei_scalar_product_op)(_expression(), other.derived());
+  return EIGEN_CWISE_PRODUCT_RETURN_TYPE(_expression(), other.derived());
 }
 
 /** \returns an expression of the coefficient-wise quotient of *this and \a other

Eigen/src/Core/Functors.h

@@ -348,11 +348,15 @@ template<typename Scalar>
 struct ei_functor_traits<ei_scalar_identity_op<Scalar> >
 { enum { Cost = NumTraits<Scalar>::AddCost, PacketAccess = false, IsRepeatable = true }; };
 
-// FIXME quick hack:
 // all functors allow linear access, except ei_scalar_identity_op. So we fix here a quick meta
 // to indicate whether a functor allows linear access, just always answering 'yes' except for
 // ei_scalar_identity_op.
 template<typename Functor> struct ei_functor_has_linear_access { enum { ret = 1 }; };
 template<typename Scalar> struct ei_functor_has_linear_access<ei_scalar_identity_op<Scalar> > { enum { ret = 0 }; };
 
+// in CwiseBinaryOp, we require the Lhs and Rhs to have the same scalar type, except for multiplication
+// where we only require them to have the same _real_ scalar type so one may multiply, say, float by complex<float>.
+template<typename Functor> struct ei_functor_allows_mixing_real_and_complex { enum { ret = 0 }; };
+template<typename Scalar> struct ei_functor_allows_mixing_real_and_complex<ei_scalar_product_op<Scalar> > { enum { ret = 1 }; };
+
 #endif // EIGEN_FUNCTORS_H

Eigen/src/Core/util/Meta.h

@@ -69,7 +69,7 @@ template<typename T> struct ei_cleantype<T*>        { typedef typename ei_cleant
   *
   * It supports both the current STL mechanism (using the result_type member) as well as
   * upcoming next STL generation (using a templated result member).
-  * If none of these members is provided, then the type of the first argument is returned.
+  * If none of these members is provided, then the type of the first argument is returned. FIXME, that behavior is a pretty bad hack.
   */
 template<typename T> struct ei_result_of {};
 
@@ -146,4 +146,38 @@ class ei_meta_sqrt
 template<int Y, int InfX, int SupX>
 class ei_meta_sqrt<Y, InfX, SupX, true> { public:  enum { ret = (SupX*SupX <= Y) ? SupX : InfX }; };
 
+/** \internal determines whether the product of two numeric types is allowed and what the return type is */
+template<typename T, typename U> struct ei_scalar_product_traits
+{
+  // dummy general case where T and U aren't compatible -- not allowed anyway but we catch it elsewhere
+  //enum { Cost = NumTraits<T>::MulCost };
+  typedef T ReturnType;
+};
+
+template<typename T> struct ei_scalar_product_traits<T,T>
+{
+  //enum { Cost = NumTraits<T>::MulCost };
+  typedef T ReturnType;
+};
+
+template<typename T> struct ei_scalar_product_traits<T,std::complex<T> >
+{
+  //enum { Cost = 2*NumTraits<T>::MulCost };
+  typedef std::complex<T> ReturnType;
+};
+
+template<typename T> struct ei_scalar_product_traits<std::complex<T>, T>
+{
+  //enum { Cost = 2*NumTraits<T>::MulCost  };
+  typedef std::complex<T> ReturnType;
+};
+
+// FIXME quick workaround around current limitation of ei_result_of
+template<typename Scalar, typename ArgType0, typename ArgType1>
+struct ei_result_of<ei_scalar_product_op<Scalar>(ArgType0,ArgType1)> {
+typedef typename ei_scalar_product_traits<typename ei_cleantype<ArgType0>::type, typename ei_cleantype<ArgType1>::type>::ReturnType type;
+};
+
+
+
 #endif // EIGEN_META_H