Unpacking nested tuples in C++

std::tie provides a convenient way to unpack the contents of a tuple in C++ into separately defined variables, like the sample below illustrates

int a, b, c, d, e, f;

auto tup1 = std::make_tuple(1, 2, 3);
std::tie(a, b, c) = tup1;

However, if we have a nested tuple like below

auto tup2 = std::make_tuple(1, 2, 3, std::make_tuple(4, 5, 6));

attempting to compile the code

std::tie(a, b, c, std::tie(d, e, f)) = tup2;

fails with an error

/tmp/tuple.cpp:10: error: invalid initialization of non-const reference of type ‘std::tuple<int&, int&, int&>&’ from an rvalue of type ‘std::tuple<int&, int&, int&>’
  std::tie(a, b, c, std::tie(d, e, f)) = tup2;
                            ^

Is there an idiomatic way to unpack a tuple of tuples in C++?