bug #1531: expose NumDimensions for compatibility with Tensor

Eigen/src/Core/DenseBase.h

diff --git a/Eigen/src/Core/DenseBase.h b/Eigen/src/Core/DenseBase.h
index 53b427b..8b994f3 100644
--- a/Eigen/src/Core/DenseBase.h
+++ b/Eigen/src/Core/DenseBase.h
@@ -157,6 +157,11 @@
           * we are dealing with a column-vector (if there is only one column) or with
           * a row-vector (if there is only one row). */
 
+      NumDimensions = int(MaxSizeAtCompileTime) == 1 ? 0 : bool(IsVectorAtCompileTime) ? 1 : 2,
+        /**< This value is equal to Tensor::NumDimensions, i.e. 0 for scalars, 1 for vectors, 
+         * and 2 for matrices.
+         */
+
       Flags = internal::traits<Derived>::Flags,
         /**< This stores expression \ref flags flags which may or may not be inherited by new expressions
           * constructed from this one. See the \ref flags "list of flags".

test/indexed_view.cpp

diff --git a/test/indexed_view.cpp b/test/indexed_view.cpp
index 2d46ffd..551dc55 100644
--- a/test/indexed_view.cpp
+++ b/test/indexed_view.cpp
@@ -397,10 +397,6 @@
 //   }
 
   // static checks of some internals:
-
-  #define STATIC_CHECK( COND ) \
-    EIGEN_STATIC_ASSERT( (COND) , EIGEN_INTERNAL_ERROR_PLEASE_FILE_A_BUG_REPORT )
-
   STATIC_CHECK(( internal::is_valid_index_type<int>::value ));
   STATIC_CHECK(( internal::is_valid_index_type<unsigned int>::value ));
   STATIC_CHECK(( internal::is_valid_index_type<short>::value ));

test/main.h

diff --git a/test/main.h b/test/main.h
index a94e1ab..9c8148d 100644
--- a/test/main.h
+++ b/test/main.h
@@ -339,6 +339,8 @@
 
 #define VERIFY_IS_UNITARY(a) VERIFY(test_isUnitary(a))
 
+#define STATIC_CHECK(COND) EIGEN_STATIC_ASSERT( (COND) , EIGEN_INTERNAL_ERROR_PLEASE_FILE_A_BUG_REPORT )
+
 #define CALL_SUBTEST(FUNC) do { \
     g_test_stack.push_back(EI_PP_MAKE_STRING(FUNC)); \
     FUNC; \

test/mapped_matrix.cpp

diff --git a/test/mapped_matrix.cpp b/test/mapped_matrix.cpp
index 6a84c58..b9f36d8 100644
--- a/test/mapped_matrix.cpp
+++ b/test/mapped_matrix.cpp
@@ -181,6 +181,49 @@
   internal::aligned_delete(array1, (size+1)*(size+1)+1);
 }
 
+#if EIGEN_HAS_CXX11
+template<template <typename,int,int> class Object>
+void map_num_dimensions()
+{
+  typedef Object<double, 1, 1> ArrayScalarType;
+  typedef Object<double, 2, 1> ArrayVectorType;
+  typedef Object<double, 1, 2> TransposeArrayVectorType;
+  typedef Object<double, 2, 2> ArrayType;
+  typedef Object<double, Eigen::Dynamic, 1> DynamicArrayVectorType;
+  typedef Object<double, 1, Eigen::Dynamic> DynamicTransposeArrayVectorType;
+  typedef Object<double, Eigen::Dynamic, Eigen::Dynamic> DynamicArrayType;
+
+  STATIC_CHECK(ArrayScalarType::NumDimensions == 0);
+  STATIC_CHECK(ArrayVectorType::NumDimensions == 1);
+  STATIC_CHECK(TransposeArrayVectorType::NumDimensions == 1);
+  STATIC_CHECK(ArrayType::NumDimensions == 2);
+  STATIC_CHECK(DynamicArrayVectorType::NumDimensions == 1);
+  STATIC_CHECK(DynamicTransposeArrayVectorType::NumDimensions == 1);
+  STATIC_CHECK(DynamicArrayType::NumDimensions == 2);
+
+  typedef Eigen::Map<ArrayScalarType> ArrayScalarMap;
+  typedef Eigen::Map<ArrayVectorType> ArrayVectorMap;
+  typedef Eigen::Map<TransposeArrayVectorType> TransposeArrayVectorMap;
+  typedef Eigen::Map<ArrayType> ArrayMap;
+  typedef Eigen::Map<DynamicArrayVectorType> DynamicArrayVectorMap;
+  typedef Eigen::Map<DynamicTransposeArrayVectorType> DynamicTransposeArrayVectorMap;
+  typedef Eigen::Map<DynamicArrayType> DynamicArrayMap;
+
+  STATIC_CHECK(ArrayScalarMap::NumDimensions == 0);
+  STATIC_CHECK(ArrayVectorMap::NumDimensions == 1);
+  STATIC_CHECK(TransposeArrayVectorMap::NumDimensions == 1);
+  STATIC_CHECK(ArrayMap::NumDimensions == 2);
+  STATIC_CHECK(DynamicArrayVectorMap::NumDimensions == 1);
+  STATIC_CHECK(DynamicTransposeArrayVectorMap::NumDimensions == 1);
+  STATIC_CHECK(DynamicArrayMap::NumDimensions == 2);
+}
+
+template<typename Scalar, int Rows, int Cols>
+using TArray = Array<Scalar,Rows,Cols>;
+template<typename Scalar, int Rows, int Cols>
+using TMatrix = Matrix<Scalar,Rows,Cols>;
+#endif
+
 void test_mapped_matrix()
 {
   for(int i = 0; i < g_repeat; i++) {
@@ -205,7 +248,11 @@
     CALL_SUBTEST_8( map_static_methods(RowVector3d()) );
     CALL_SUBTEST_9( map_static_methods(VectorXcd(8)) );
     CALL_SUBTEST_10( map_static_methods(VectorXf(12)) );
-    
     CALL_SUBTEST_11( map_not_aligned_on_scalar<double>() );
   }
+
+  #if EIGEN_HAS_CXX11
+    CALL_SUBTEST_12( map_num_dimensions<TArray>() );
+    CALL_SUBTEST_12( map_num_dimensions<TMatrix>() );
+  #endif
 }