Join two tuples in C++11

c++, c++11, tuples

Solution

You can use `std::tuple_cat`

std::tuple<foo, bar, baz> buzz;
std::tuple<moo, meow, arf> bark;

auto my_cat_tuple = std::tuple_cat(buzz, std::move(bark));  // copy elements of buzz,
                                                            // move elements of bark

The above will work if the element types of the tuples are movable or copyable. And it does not require them to be default constructible unless you're doing something like

decltype(std::tuple_cat(buzz, bark)) my_uncatted_yet_tuple;  // This will attempt to default construct the tuple elements

my_uncatted_yet_tuple = std::tuple_cat(buzz, std::move(bark));

Problem

I've got two tuples, `std::tuple<F1, F2, ..., FN>`, `std::tuple<G1, G2, ..., GN>` (or `std::tuple<G1>` aka `G1`). Is there any way to join these tuples generically into a `std::tuple<F1, F2, ..., FN, G1, G2, ..., GN>` if any of the types `F1`, `F2`, ..., `FN`, `G1`, `G2`, ..., `GN` does not have a default constructor, but is movable / swapable?

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