std::swap(std::vector)
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swap(std::vector)
(C++20)(C++20)
(until C++20)(until C++20)(until C++20)(until C++20)(until C++20)
Deduction guides (C++17)
Defined in header
<vector>
template< class T, class Alloc >
(until C++17)
void swap( std::vector <T, Alloc>& lhs,
template< class T, class Alloc >
(since C++17) void swap( std::vector <T, Alloc>& lhs,
std::vector <T, Alloc>& rhs )
(constexpr since C++20)
Specializes the std::swap algorithm for std::vector . Swaps the contents of lhs and rhs. Calls lhs.swap(rhs).
[edit] Parameters
lhs, rhs
-
containers whose contents to swap
[edit] Complexity
Constant.
Exceptions
noexcept specification:
(since C++17)noexcept(noexcept(lhs.swap(rhs)))
[edit] 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 << "\nBobby:"; 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 << "\nBobby:"; std::for_each (bob.begin(), bob.end(), print); std::cout << '\n'; }
Output:
Alice: 1 2 3 Bobby: 7 8 9 10 -- SWAP Alice: 7 8 9 10 Bobby: 1 2 3