std::tuple<Types...>::swap

Defined in header `<tuple>`
void swap( tuple& other ) noexcept(/* see below */);		(since C++11) (until C++20)
constexpr void swap( tuple& other ) noexcept(/* see below */);		(since C++20)

Calls swap (which might be std::swap, or might be found via ADL) for each element in *this and its corresponding element in other.

Parameters

other

tuple of values to swap

Return value

(none).

Exceptions

`noexcept` specification: `noexcept( noexcept(swap(std::declval<T0&>>(), std::declval<T0&>())) && noexcept(swap(std::declval<T1&>>(), std::declval<T1&>())) && noexcept(swap(std::declval<T2&>>(), std::declval<T2&>())) && ... )` In the expression above, the identifier `swap` is looked up in the same manner as the one used by the C++17 `std::is_nothrow_swappable` trait.	(until C++17)
`noexcept` specification: `noexcept( std::is_nothrow_swappable_v<T0> && std::is_nothrow_swappable_v<T1> && std::is_nothrow_swappable_v<T2> && ... )`	(since C++17)

Example

#include <iostream>
#include <tuple>
#include <string>
 
int main()
{
    std::tuple<int, std::string, float> p1, p2;
    p1 = std::make_tuple(10, "test", 3.14);
    p2.swap(p1);
    std::cout << "("  << std::get<0>(p2)
              << ", " << std::get<1>(p2)
              << ", " << std::get<2>(p2) << ")\n";
}

Output:

(10, test, 3.14)

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 2456	C++11	the `noexcept` specification is ill-formed	made to work