Define Permutation*<>::Scalar to 'void', re-enable scalar type compatibility check in assignment while relaxing this test for void types.

3 files changed, 11 insertions, 7 deletions

diff --git a/Eigen/src/Core/AssignEvaluator.h b/Eigen/src/Core/AssignEvaluator.h
index f94539094..a02104bb0 100644
--- a/Eigen/src/Core/AssignEvaluator.h
+++ b/Eigen/src/Core/AssignEvaluator.h
@@ -751,11 +751,7 @@ EIGEN_DEVICE_FUNC void call_assignment_no_alias(Dst& dst, const Src& src, const
   // TODO check whether this is the right place to perform these checks:
   EIGEN_STATIC_ASSERT_LVALUE(Dst)
   EIGEN_STATIC_ASSERT_SAME_MATRIX_SIZE(ActualDstTypeCleaned,Src)
-
-  // TODO this line is commented to allow matrix = permutation
-  // Actually, the "Scalar" type for a permutation matrix does not really make sense,
-  // perhaps it could be void, and EIGEN_CHECK_BINARY_COMPATIBILIY could allow micing void with anything...?
-//   EIGEN_CHECK_BINARY_COMPATIBILIY(Func,typename ActualDstTypeCleaned::Scalar,typename Src::Scalar);
+  EIGEN_CHECK_BINARY_COMPATIBILIY(Func,typename ActualDstTypeCleaned::Scalar,typename Src::Scalar);
   
   Assignment<ActualDstTypeCleaned,Src,Func>::run(actualDst, src, func);
 }
diff --git a/Eigen/src/Core/PermutationMatrix.h b/Eigen/src/Core/PermutationMatrix.h
index bfe6f899a..b5f7e4a54 100644
--- a/Eigen/src/Core/PermutationMatrix.h
+++ b/Eigen/src/Core/PermutationMatrix.h
@@ -69,6 +69,7 @@ class PermutationBase : public EigenBase<Derived>
             PlainPermutationType;
     using Base::derived;
     typedef Transpose<PermutationBase> TransposeReturnType;
+    typedef void Scalar;
     #endif
 
     /** Copies the other permutation into *this */
@@ -303,6 +304,7 @@ struct traits<PermutationMatrix<SizeAtCompileTime, MaxSizeAtCompileTime, _Storag
   typedef PermutationStorage StorageKind;
   typedef Matrix<_StorageIndex, SizeAtCompileTime, 1, 0, MaxSizeAtCompileTime, 1> IndicesType;
   typedef _StorageIndex StorageIndex;
+  typedef void Scalar;
 };
 }
 
@@ -426,6 +428,7 @@ struct traits<Map<PermutationMatrix<SizeAtCompileTime, MaxSizeAtCompileTime, _St
   typedef PermutationStorage StorageKind;
   typedef Map<const Matrix<_StorageIndex, SizeAtCompileTime, 1, 0, MaxSizeAtCompileTime, 1>, _PacketAccess> IndicesType;
   typedef _StorageIndex StorageIndex;
+  typedef void Scalar;
 };
 }
 
@@ -499,7 +502,7 @@ template<typename _IndicesType>
 struct traits<PermutationWrapper<_IndicesType> >
 {
   typedef PermutationStorage StorageKind;
-  typedef typename _IndicesType::Scalar Scalar;
+  typedef void Scalar;
   typedef typename _IndicesType::Scalar StorageIndex;
   typedef _IndicesType IndicesType;
   enum {
diff --git a/Eigen/src/Core/util/XprHelper.h b/Eigen/src/Core/util/XprHelper.h
index c31cd4801..052f824ae 100644
--- a/Eigen/src/Core/util/XprHelper.h
+++ b/Eigen/src/Core/util/XprHelper.h
@@ -654,6 +654,11 @@ bool is_same_dense(const T1 &, const T2 &, typename enable_if<!(has_direct_acces
   return false;
 }
 
+template<typename T, typename U> struct is_same_or_void { enum { value = is_same<T,U>::value }; };
+template<typename T> struct is_same_or_void<void,T>     { enum { value = 1 }; };
+template<typename T> struct is_same_or_void<T,void>     { enum { value = 1 }; };
+template<>           struct is_same_or_void<void,void>  { enum { value = 1 }; };
+
 } // end namespace internal
 
 // we require Lhs and Rhs to have the same scalar type. Currently there is no example of a binary functor
@@ -666,7 +671,7 @@ bool is_same_dense(const T1 &, const T2 &, typename enable_if<!(has_direct_acces
 #define EIGEN_CHECK_BINARY_COMPATIBILIY(BINOP,LHS,RHS) \
   EIGEN_STATIC_ASSERT((internal::functor_is_product_like<BINOP>::ret \
                         ? int(internal::scalar_product_traits<LHS, RHS>::Defined) \
-                        : int(internal::is_same<LHS, RHS>::value)), \
+                        : int(internal::is_same_or_void<LHS, RHS>::value)), \
     YOU_MIXED_DIFFERENT_NUMERIC_TYPES__YOU_NEED_TO_USE_THE_CAST_METHOD_OF_MATRIXBASE_TO_CAST_NUMERIC_TYPES_EXPLICITLY)
     
 } // end namespace Eigen