From 1a36590e8475f688ef42122c0dd96f7a3b89654e Mon Sep 17 00:00:00 2001
From: Benoit Steiner <benoit.steiner.goog@gmail.com>
Date: Wed, 14 Jan 2015 12:43:20 -0800
Subject: [PATCH] Fixed the printing of RowMajor tensors

---
 unsupported/Eigen/CXX11/src/Tensor/TensorIO.h | 15 ++++-
 unsupported/test/cxx11_tensor_io.cpp          | 58 ++++++++++++++++---
 2 files changed, 63 insertions(+), 10 deletions(-)

diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorIO.h b/unsupported/Eigen/CXX11/src/Tensor/TensorIO.h
index 959b5db73..a9d0f6c39 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorIO.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorIO.h
@@ -12,6 +12,14 @@
 
 namespace Eigen {
 
+namespace internal {
+template<>
+struct significant_decimals_impl<std::string>
+    : significant_decimals_default_impl<std::string, true>
+{};
+}
+
+
 template <typename T>
 std::ostream& operator << (std::ostream& os, const TensorBase<T, ReadOnlyAccessors>& expr) {
   // Evaluate the expression if needed
@@ -19,18 +27,19 @@ std::ostream& operator << (std::ostream& os, const TensorBase<T, ReadOnlyAccesso
   TensorEvaluator<const TensorForcedEvalOp<const T>, DefaultDevice> tensor(eval, DefaultDevice());
   tensor.evalSubExprsIfNeeded(NULL);
 
-  typedef typename T::Scalar Scalar;
+  typedef typename internal::remove_const<typename T::Scalar>::type Scalar;
   typedef typename T::Index Index;
   typedef typename TensorEvaluator<const TensorForcedEvalOp<const T>, DefaultDevice>::Dimensions Dimensions;
   const Index total_size = internal::array_prod(tensor.dimensions());
 
   // Print the tensor as a 1d vector or a 2d matrix.
   if (internal::array_size<Dimensions>::value == 1) {
-    Map<Array<Scalar, Dynamic, 1> > array(tensor.data(), total_size);
+    Map<const Array<Scalar, Dynamic, 1> > array(const_cast<Scalar*>(tensor.data()), total_size);
     os << array;
   } else {
     const Index first_dim = tensor.dimensions()[0];
-    Map<Array<Scalar, Dynamic, Dynamic> > matrix(tensor.data(), first_dim, total_size/first_dim);
+    static const int layout = TensorEvaluator<const TensorForcedEvalOp<const T>, DefaultDevice>::Layout;
+    Map<const Array<Scalar, Dynamic, Dynamic, layout> > matrix(const_cast<Scalar*>(tensor.data()), first_dim, total_size/first_dim);
     os << matrix;
   }
 
diff --git a/unsupported/test/cxx11_tensor_io.cpp b/unsupported/test/cxx11_tensor_io.cpp
index b73c024f5..8bbcf7089 100644
--- a/unsupported/test/cxx11_tensor_io.cpp
+++ b/unsupported/test/cxx11_tensor_io.cpp
@@ -13,9 +13,10 @@
 #include <Eigen/CXX11/Tensor>
 
 
+template<int DataLayout>
 static void test_output_1d()
 {
-  Tensor<int, 1> tensor(5);
+  Tensor<int, 1, DataLayout> tensor(5);
   for (int i = 0; i < 5; ++i) {
     tensor(i) = i;
   }
@@ -28,9 +29,10 @@ static void test_output_1d()
 }
 
 
+template<int DataLayout>
 static void test_output_2d()
 {
-  Tensor<int, 2> tensor(5, 3);
+  Tensor<int, 2, DataLayout> tensor(5, 3);
   for (int i = 0; i < 5; ++i) {
     for (int j = 0; j < 3; ++j) {
       tensor(i, j) = i*j;
@@ -45,10 +47,11 @@ static void test_output_2d()
 }
 
 
+template<int DataLayout>
 static void test_output_expr()
 {
-  Tensor<int, 1> tensor1(5);
-  Tensor<int, 1> tensor2(5);
+  Tensor<int, 1, DataLayout> tensor1(5);
+  Tensor<int, 1, DataLayout> tensor2(5);
   for (int i = 0; i < 5; ++i) {
     tensor1(i) = i;
     tensor2(i) = 7;
@@ -62,9 +65,50 @@ static void test_output_expr()
 }
 
 
+template<int DataLayout>
+static void test_output_string()
+{
+  Tensor<std::string, 2, DataLayout> tensor(5, 3);
+  tensor.setConstant(std::string("foo"));
+
+  std::cout << tensor << std::endl;
+
+  std::stringstream os;
+  os << tensor;
+
+  std::string expected("foo  foo  foo\nfoo  foo  foo\nfoo  foo  foo\nfoo  foo  foo\nfoo  foo  foo");
+  VERIFY_IS_EQUAL(std::string(os.str()), expected);
+}
+
+
+template<int DataLayout>
+static void test_output_const()
+{
+  Tensor<int, 1, DataLayout> tensor(5);
+  for (int i = 0; i < 5; ++i) {
+    tensor(i) = i;
+  }
+
+  TensorMap<Tensor<const int, 1, DataLayout> > tensor_map(tensor.data(), 5);
+
+  std::stringstream os;
+  os << tensor_map;
+
+  std::string expected("0\n1\n2\n3\n4");
+  VERIFY_IS_EQUAL(std::string(os.str()), expected);
+}
+
+
 void test_cxx11_tensor_io()
 {
-  CALL_SUBTEST(test_output_1d());
-  CALL_SUBTEST(test_output_2d());
-  CALL_SUBTEST(test_output_expr());
+  CALL_SUBTEST(test_output_1d<ColMajor>());
+  CALL_SUBTEST(test_output_1d<RowMajor>());
+  CALL_SUBTEST(test_output_2d<ColMajor>());
+  CALL_SUBTEST(test_output_2d<RowMajor>());
+  CALL_SUBTEST(test_output_expr<ColMajor>());
+  CALL_SUBTEST(test_output_expr<RowMajor>());
+  CALL_SUBTEST(test_output_string<ColMajor>());
+  CALL_SUBTEST(test_output_string<RowMajor>());
+  CALL_SUBTEST(test_output_const<ColMajor>());
+  CALL_SUBTEST(test_output_const<RowMajor>());
 }