std::swap(std::tuple)

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std::tuple

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tuple::swap
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Defined in header`<tuple>`
	(1)
template<class...Types> void swap(std::tuple<Types...>& lhs, std::tuple<Types...>& rhs)noexcept(/* see below */);			(since C++11) (until C++20)
template<class...Types> constexprvoid swap(std::tuple<Types...>& lhs, std::tuple<Types...>& rhs)noexcept(/* see below */);			(since C++20)
template<class...Types> constexprvoid swap(conststd::tuple<Types...>& lhs, conststd::tuple<Types...>& rhs)noexcept(/* see below */);		(2)	(since C++23)

Swaps the contents oflhs andrhs. Equivalent tolhs.swap(rhs).

1) This overload participates in overload resolution only ifstd::is_swappable_v<Ti> istrue for all i from 0 tosizeof...(Types).

2) This overload participates in overload resolution only ifstd::is_swappable_v<const Ti> istrue for all i from 0 tosizeof...(Types).

(since C++17)

[edit]Parameters

lhs, rhs

tuples whose contents to swap

[edit]Return value

(none)

[edit]Exceptions

noexcept specification:

noexcept(noexcept(lhs.swap(rhs)))

[edit]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}

[edit]See also

swap	swaps the contents of two`tuple`s (public member function)[edit]
std::swap(std::pair) (C++11)	specializes thestd::swap algorithm (function template)[edit]