NAME¶

std::swap(std::vector) - std::swap(std::vector)

Synopsis¶

Defined in header <vector>
template< class T, class Alloc >

void swap( std::vector<T, Alloc>& lhs, (until C++17)

std::vector<T, Alloc>& rhs );
template< class T, class Alloc >

void swap( std::vector<T, Alloc>& lhs, (since C++17)
std::vector<T, Alloc>& rhs ) (constexpr since C++20)

noexcept(/* see below */);

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

Parameters¶

lhs, rhs - containers whose contents to swap

Return value¶

(none)

Complexity¶

Constant.

Exceptions¶

noexcept specification: (since C++17)
noexcept(noexcept(lhs.swap(rhs)))

Example¶

// Run this code

#include <algorithm>
#include <iostream>
#include <vector>

int main()
{
std::vector<int> alice{1, 2, 3};
std::vector<int> bob{7, 8, 9, 10};

auto print = [](const int& n) { std::cout << ' ' << n; };

// 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 2 3
Bob : 7 8 9 10
-- SWAP
Alice: 7 8 9 10
Bob : 1 2 3

See also¶

swap swaps the contents
(public member function)

Category:¶

* conditionally noexcept