std::swap(std::tuple)(3)

NAME
std::swap(std::tuple) - std::swap(std::tuple)

Synopsis
   Defined in header <tuple>
   template< class... Types >
   void swap( std::tuple<Types...>& lhs, (since C++11)
                        (until C++20)
              std::tuple<Types...>& rhs ) noexcept(/* see below
   */);
   template< class... Types >
   constexpr void swap( std::tuple<Types...>& lhs, (1) (since C++20)
                        std::tuple<Types...>& rhs ) noexcept(/*
   see below */);
   template< class... Types >
   constexpr void swap( const std::tuple<Types...>& lhs, (2) (since C++23)
                        const std::tuple<Types...>& rhs )
   noexcept(/* see below */);
   Swaps the contents of lhs and rhs. Equivalent to lhs.swap(rhs).
   1) This overload participates in overload resolution only if
   std::is_swappable_v<Ti> is true for all i from 0 to sizeof...(Types).
   2) This overload participates in overload resolution only if (since C++17)
   std::is_swappable_v<const Ti> is true for all i from 0 to
   sizeof...(Types).

Parameters
   lhs, rhs - tuples whose contents to swap

Return value
   (none)

Exceptions
   noexcept specification:
   noexcept(noexcept(lhs.swap(rhs)))

Example
// Run this code
 #include <iostream>
 #include <string>
 #include <tuple>
 int main()
 {
     std::tuple<int, std::string, float> p1{42, "ABCD", 2.71}, p2;
     p2 = std::make_tuple(10, "1234", 3.14);
     auto print_p1_p2 = [&](auto rem)
     {
         std::cout << rem
                   << "p1 = {" << std::get<0>(p1)
                   << ", " << std::get<1>(p1)
                   << ", " << std::get<2>(p1) << "}, "
                   << "p2 = {" << std::get<0>(p2)
                   << ", " << std::get<1>(p2)
                   << ", " << std::get<2>(p2) << "}\n";
     };
     print_p1_p2("Before p1.swap(p2): ");
     p1.swap(p2);
     print_p1_p2("After p1.swap(p2): ");
     swap(p1, p2);
     print_p1_p2("After swap(p1, p2): ");
 }

Output:
 Before p1.swap(p2): p1 = {42, ABCD, 2.71}, p2 = {10, 1234, 3.14}
 After p1.swap(p2): p1 = {10, 1234, 3.14}, p2 = {42, ABCD, 2.71}
 After swap(p1, p2): p1 = {42, ABCD, 2.71}, p2 = {10, 1234, 3.14}

See also
   swap swaps the contents of two tuples
                        (public member function)
   std::swap(std::pair) specializes the std::swap algorithm
   (C++11) (function template)

Category:
     * conditionally noexcept