NAME

std::swap(std::flat_map) - std::swap(std::flat_map)

Synopsis

Defined in header <flat_map>
friend void swap( std::flat_map& lhs, std::flat_map& rhs ) noexcept; (since C++23)

Specializes the std::swap algorithm for std::flat_map. Swaps the contents of lhs and
rhs. Calls lhs.swap(rhs).

Parameters

lhs, rhs - containers whose contents to swap

Return value

(none)

Complexity

Same as swapping the underlying containers.

Example

// Run this code

#include <algorithm>
#include <iostream>
#include <flat_map>

int main()
{
std::flat_map<int, char> alice{{1, 'a'}, {2, 'b'}, {3, 'c'}};
std::flat_map<int, char> bob{{7, 'Z'}, {8, 'Y'}, {9, 'X'}, {10, 'W'}};

auto print = [](std::pair<const int, char>& n)
{
std::cout << ' ' << n.first << ':' << n.second;
};

// Print state before swap
std::cout << "Alice:";
std::for_each(alice.begin(), alice.end(), print);
std::cout << "\n" "Bob :";
std::for_each(bob.begin(), bob.end(), print);
std::cout << '\n';

std::cout << "-- SWAP\n";
std::swap(alice, bob);

// Print state after swap
std::cout << "Alice:";
std::for_each(alice.begin(), alice.end(), print);
std::cout << "\n" "Bob :";
std::for_each(bob.begin(), bob.end(), print);
std::cout << '\n';
}

Output:

Alice: 1:a 2:b 3:c
Bob : 7:Z 8:Y 9:X 10:W
-- SWAP
Alice: 7:Z 8:Y 9:X 10:W
Bob : 1:a 2:b 3:c