From 1b40abbf99d2022d1167063f7e52126cbe8d76bd Mon Sep 17 00:00:00 2001
From: Benoit Steiner <benoit.steiner.goog@gmail.com>
Date: Wed, 30 Mar 2016 13:17:03 -0700
Subject: [PATCH] Added missing assignment operator to the TensorUInt128 class,
 and made misc small improvements

---
 unsupported/Eigen/CXX11/src/Tensor/TensorUInt128.h | 13 ++++++++++++-
 unsupported/test/cxx11_tensor_uint128.cpp          |  2 +-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorUInt128.h b/unsupported/Eigen/CXX11/src/Tensor/TensorUInt128.h
index 02d6646d8..543a444fb 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorUInt128.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorUInt128.h
@@ -40,14 +40,25 @@ struct TensorUInt128
     EIGEN_STATIC_ASSERT(sizeof(OTHER_LOW) <= sizeof(LOW), YOU_MADE_A_PROGRAMMING_MISTAKE);
   }
 
+  template<typename OTHER_HIGH, typename OTHER_LOW>
+  EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
+  TensorUInt128& operator = (const TensorUInt128<OTHER_HIGH, OTHER_LOW>& other) {
+    EIGEN_STATIC_ASSERT(sizeof(OTHER_HIGH) <= sizeof(HIGH), YOU_MADE_A_PROGRAMMING_MISTAKE);
+    EIGEN_STATIC_ASSERT(sizeof(OTHER_LOW) <= sizeof(LOW), YOU_MADE_A_PROGRAMMING_MISTAKE);
+    high = other.high;
+    low = other.low;
+    return *this;
+  }
+
   template<typename T>
   EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   explicit TensorUInt128(const T& x) : high(0), low(x) {
+    eigen_assert(x < NumTraits<LOW>::highest());
     eigen_assert(x >= 0);
   }
 
   EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
-  TensorUInt128(uint64_t y, uint64_t x) : high(y), low(x) { }
+  TensorUInt128(HIGH y, LOW x) : high(y), low(x) { }
 
   EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE operator LOW() const {
     return low;
diff --git a/unsupported/test/cxx11_tensor_uint128.cpp b/unsupported/test/cxx11_tensor_uint128.cpp
index 2cbc45716..d2a1e8673 100644
--- a/unsupported/test/cxx11_tensor_uint128.cpp
+++ b/unsupported/test/cxx11_tensor_uint128.cpp
@@ -147,7 +147,7 @@ void test_misc2() {
 void test_cxx11_tensor_uint128()
 {
 #ifdef EIGEN_NO_INT128
-  // Skip the test on compilers that don't support 128bit integers natively 
+  // Skip the test on compilers that don't support 128bit integers natively
   return;
 #else
   CALL_SUBTEST_1(test_add());