1 files changed, 59 insertions, 9 deletions

diff --git a/unsupported/test/cxx11_tensor_map.cpp b/unsupported/test/cxx11_tensor_map.cpp
index 3db0ee7c0..4d4f68911 100644
--- a/unsupported/test/cxx11_tensor_map.cpp
+++ b/unsupported/test/cxx11_tensor_map.cpp
@@ -19,8 +19,8 @@ static void test_0d()
   Tensor<int, 0> scalar1;
   Tensor<int, 0, RowMajor> scalar2;
 
-  TensorMap<Tensor<const int, 0> > scalar3(scalar1.data());
-  TensorMap<Tensor<const int, 0, RowMajor> > scalar4(scalar2.data());
+  TensorMap<const Tensor<int, 0> > scalar3(scalar1.data());
+  TensorMap<const Tensor<int, 0, RowMajor> > scalar4(scalar2.data());
 
   scalar1() = 7;
   scalar2() = 13;
@@ -37,8 +37,8 @@ static void test_1d()
   Tensor<int, 1> vec1(6);
   Tensor<int, 1, RowMajor> vec2(6);
 
-  TensorMap<Tensor<const int, 1> > vec3(vec1.data(), 6);
-  TensorMap<Tensor<const int, 1, RowMajor> > vec4(vec2.data(), 6);
+  TensorMap<const Tensor<int, 1> > vec3(vec1.data(), 6);
+  TensorMap<const Tensor<int, 1, RowMajor> > vec4(vec2.data(), 6);
 
   vec1(0) = 4;  vec2(0) = 0;
   vec1(1) = 8;  vec2(1) = 1;
@@ -85,8 +85,8 @@ static void test_2d()
   mat2(1,1) = 4;
   mat2(1,2) = 5;
 
-  TensorMap<Tensor<const int, 2> > mat3(mat1.data(), 2, 3);
-  TensorMap<Tensor<const int, 2, RowMajor> > mat4(mat2.data(), 2, 3);
+  TensorMap<const Tensor<int, 2> > mat3(mat1.data(), 2, 3);
+  TensorMap<const Tensor<int, 2, RowMajor> > mat4(mat2.data(), 2, 3);
 
   VERIFY_IS_EQUAL(mat3.rank(), 2);
   VERIFY_IS_EQUAL(mat3.size(), 6);
@@ -129,8 +129,8 @@ static void test_3d()
     }
   }
 
-  TensorMap<Tensor<const int, 3> > mat3(mat1.data(), 2, 3, 7);
-  TensorMap<Tensor<const int, 3, RowMajor> > mat4(mat2.data(), 2, 3, 7);
+  TensorMap<const Tensor<int, 3> > mat3(mat1.data(), 2, 3, 7);
+  TensorMap<const Tensor<int, 3, RowMajor> > mat4(mat2.data(), 2, 3, 7);
 
   VERIFY_IS_EQUAL(mat3.rank(), 3);
   VERIFY_IS_EQUAL(mat3.size(), 2*3*7);
@@ -265,7 +265,54 @@ static void test_casting()
   VERIFY_IS_EQUAL(sum1, 861);
 }
 
-void test_cxx11_tensor_map()
+template<typename T>
+static const T& add_const(T& value) {
+  return value;
+}
+
+static void test_0d_const_tensor()
+{
+  Tensor<int, 0> scalar1;
+  Tensor<int, 0, RowMajor> scalar2;
+
+  TensorMap<const Tensor<int, 0> > scalar3(add_const(scalar1).data());
+  TensorMap<const Tensor<int, 0, RowMajor> > scalar4(add_const(scalar2).data());
+
+  scalar1() = 7;
+  scalar2() = 13;
+
+  VERIFY_IS_EQUAL(scalar1.rank(), 0);
+  VERIFY_IS_EQUAL(scalar1.size(), 1);
+
+  VERIFY_IS_EQUAL(scalar3(), 7);
+  VERIFY_IS_EQUAL(scalar4(), 13);
+}
+
+static void test_0d_const_tensor_map()
+{
+  Tensor<int, 0> scalar1;
+  Tensor<int, 0, RowMajor> scalar2;
+
+  const TensorMap<Tensor<int, 0> > scalar3(scalar1.data());
+  const TensorMap<Tensor<int, 0, RowMajor> > scalar4(scalar2.data());
+
+  // Although TensorMap is constant, we still can write to the underlying
+  // storage, because we map over non-constant Tensor.
+  scalar3() = 7;
+  scalar4() = 13;
+
+  VERIFY_IS_EQUAL(scalar1(), 7);
+  VERIFY_IS_EQUAL(scalar2(), 13);
+
+  // Pointer to the underlying storage is also non-const.
+  scalar3.data()[0] = 8;
+  scalar4.data()[0] = 14;
+
+  VERIFY_IS_EQUAL(scalar1(), 8);
+  VERIFY_IS_EQUAL(scalar2(), 14);
+}
+
+EIGEN_DECLARE_TEST(cxx11_tensor_map)
 {
   CALL_SUBTEST(test_0d());
   CALL_SUBTEST(test_1d());
@@ -274,4 +321,7 @@ void test_cxx11_tensor_map()
 
   CALL_SUBTEST(test_from_tensor());
   CALL_SUBTEST(test_casting());
+
+  CALL_SUBTEST(test_0d_const_tensor());
+  CALL_SUBTEST(test_0d_const_tensor_map());
 }