// happen if `offset` is not block-aligned, and the read returns the last
      // block in the file, which does not extend all the way out to `offset`.
      std::stringstream os;
      os << "EOF at offset " << offset << " in file " << filename
         << " at position " << pos << " with data size " << data.size();
      TF_SetStatus(status, TF_OUT_OF_RANGE, std::move(os).str().c_str());

  // one element for each field.
  template <typename Tuple>
  static void TersePrintPrefixToStrings(const Tuple& t, Strings* strings) {
    TuplePrefixPrinter<N - 1>::TersePrintPrefixToStrings(t, strings);
    ::std::stringstream ss;
    UniversalTersePrint(::std::tr1::get<N - 1>(t), &ss);
    strings->push_back(ss.str());
  }
};

// Base cases.
template <>
struct TuplePrefixPrinter<0> {
  template <typename Tuple>

  // one element for each field.
  template <typename Tuple>
  static void TersePrintPrefixToStrings(const Tuple& t, Strings* strings) {
    TuplePrefixPrinter<N - 1>::TersePrintPrefixToStrings(t, strings);
    ::std::stringstream ss;
    UniversalTersePrint(::std::tr1::get<N - 1>(t), &ss);
    strings->push_back(ss.str());
  }
};

// Base cases.
template <>
struct TuplePrefixPrinter<0> {
  template <typename Tuple>

  if (lhs.AlmostEquals(rhs)) {
    return AssertionSuccess();
  }

  ::std::stringstream expected_ss;
  expected_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
              << expected;

  ::std::stringstream actual_ss;
  actual_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
            << actual;

  if (lhs.AlmostEquals(rhs)) {
    return AssertionSuccess();
  }

  ::std::stringstream expected_ss;
  expected_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
              << expected;

  ::std::stringstream actual_ss;
  actual_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
            << actual;

    tensorflow::FunctionDef fdef;
    EXPECT_TRUE(GetFunctionDef(func_, &fdef));
    return fdef;
  }

  // logging utility
  template <class Container>
  string ToString(const Container& v) {
    std::stringstream ss;
    ss << "{";
    size_t i = 0;
    for (const auto& e : v) {
      if (i != 0) {
        ss << ", ";
      }
      ss << e.ToString();
      ++i;
    }
    ss << "}";