table of contents
std::swap(std::multimap)(3) | C++ Standard Libary | std::swap(std::multimap)(3) |
NAME¶
std::swap(std::multimap) - std::swap(std::multimap)
Synopsis¶
Defined in header <map>
template< class Key, class T, class Compare, class Alloc >
void swap( std::multimap<Key,T,Compare,Alloc>& lhs, (until
C++17)
std::multimap<Key,T,Compare,Alloc>& rhs );
template< class Key, class T, class Compare, class Alloc >
void swap( std::multimap<Key,T,Compare,Alloc>& lhs, (since
C++17)
std::multimap<Key,T,Compare,Alloc>& rhs ) noexcept(/* see below
*/);
Specializes the std::swap algorithm for std::multimap. 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)))
Notes¶
Although the overloads of std::swap for container adaptors are
introduced in C++11,
container adaptors can already be swapped by std::swap in C++98. Such calls
to
std::swap usually have linear time complexity, but better complexity may be
provided.
Example¶
// Run this code
#include <algorithm>
#include <iostream>
#include <map>
int main()
{
std::multimap<int, char> alice{{1, 'a'}, {2, 'b'}, {3, 'c'}};
std::multimap<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)
See also¶
swap swaps the contents
(public member function)
2022.07.31 | http://cppreference.com |