std::tuple_cat (3) Linux Manual Page

std::tuple_cat – std::tuple_cat

Synopsis

Defined in header <tuple>
template< class… Tuples > (since C++11)
std::tuple<CTypes…> tuple_cat(Tuples&&… args); (constexpr since C++14)
Constructs a tuple that is a concatenation of all tuples in args.

Parameters

args – zero or more tuples to concatenate

Return value

A std::tuple object composed of all elements of all argument tuples constructed from std::get<i>(std::forward<Ti>(arg)) for each individual element.

Example

// Run this code

#include <iostream>

#include <tuple>

#include <string>
// helper function to print a tuple of any size

template <class Tuple, std::size_t N>

struct TuplePrinter {
    static void print(const Tuple &t)
    {
        TuplePrinter<Tuple, N - 1>::print(t);
        std::cout << ", " << std::get<N - 1>(t);
    }
};
template <class Tuple>

struct TuplePrinter<Tuple, 1> {
    static void print(const Tuple &t)
    {
        std::cout << std::get<0>(t);
    }
};

  template<class… Args>
  void print(const std::tuple<Args…>& t)
  {
      std::cout << "(";
      TuplePrinter<decltype(t), sizeof…(Args)>::print(t);
      std::cout << ")\n";
  }
  // end helper function

int main()

{
    std::tuple<int, std::string, float> t1(10, "Test", 3.14);
    int n = 7;
    auto t2 = std::tuple_cat(t1, std::make_pair("Foo", "bar"), t1, std::tie(n));
    n = 10;
    print(t2);
}

Output:

  (10, Test, 3.14, Foo, bar, 10, Test, 3.14, 10)

See also

                 creates a tuple object of the type defined by the argument types
make_tuple (function template)
                 creates a tuple of lvalue references or unpacks a tuple into individual objects
tie (function template)
                 creates a tuple of rvalue references
forward_as_tuple (function template)