Deleted an invalid assertion that prevented the assignment of empty tensors.

diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorStorage.h b/unsupported/Eigen/CXX11/src/Tensor/TensorStorage.h
index 98631fc..18a916e 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorStorage.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorStorage.h

@@ -105,7 +105,6 @@
 
     EIGEN_DEVICE_FUNC void resize(Index size, const array<Index, NumIndices_>& nbDimensions)
     {
-      eigen_assert(size >= 1);
       const Index currentSz = internal::array_prod(m_dimensions);
       if(size != currentSz)
       {

diff --git a/unsupported/test/CMakeLists.txt b/unsupported/test/CMakeLists.txt
index 3a90a53..d70bf2b 100644
--- a/unsupported/test/CMakeLists.txt
+++ b/unsupported/test/CMakeLists.txt

@@ -147,6 +147,7 @@
   ei_add_test(cxx11_tensor_sugar "-std=c++0x")
   ei_add_test(cxx11_tensor_fft "-std=c++0x")
   ei_add_test(cxx11_tensor_ifft "-std=c++0x")
+  ei_add_test(cxx11_tensor_empty "-std=c++0x")
 
 endif()
 

diff --git a/unsupported/test/cxx11_tensor_empty.cpp b/unsupported/test/cxx11_tensor_empty.cpp
new file mode 100644
index 0000000..ca03a29
--- /dev/null
+++ b/unsupported/test/cxx11_tensor_empty.cpp

@@ -0,0 +1,36 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2015 Benoit Steiner <benoit.steiner.goog@gmail.com>
+//
+// This Source Code Form is subject to the terms of the Mozilla
+// Public License v. 2.0. If a copy of the MPL was not distributed
+// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include "main.h"
+
+#include <Eigen/CXX11/Tensor>
+
+
+static void test_empty_tensor()
+{
+  Tensor<float, 2> source;
+  Tensor<float, 2> tgt1 = source;
+  Tensor<float, 2> tgt2;
+  tgt2 = source;
+}
+
+static void test_empty_fixed_size_tensor()
+{
+  TensorFixedSize<float, Sizes<0>> source;
+  TensorFixedSize<float, Sizes<0>> tgt1 = source;
+  TensorFixedSize<float, Sizes<0>> tgt2;
+  tgt2 = source;
+}
+
+
+void test_cxx11_tensor_empty()
+{
+   CALL_SUBTEST(test_empty_tensor());
+   CALL_SUBTEST(test_empty_fixed_size_tensor());
+}