Description : The map::swap() function exchanges the content of two maps of same type, although the size may differ. Syntax: std::swap(first_map, second_map);
Example:
// Demonstrates swap()
#include<iostream>
#include<map>
int main(){
std::map<int, char> map1, map2;
map1[1] = 'a';
map1[2] = 'b';
map1[3] = 'c';
map1[4] = 'd';
map2[5] = 'x';
map2[6] = 'y';
map2[7] = 'z';
// swap elements of map
map1.swap(map2);
std::cout << "after swapping"<<std::endl;
// print the elements of the map
std::cout << "map1 contains: ";
for (std::map<int, char>::iterator i = map1.begin(); i != map1.end(); i++){
std::cout << i->first << " => " << i->second << ", ";
}
std::cout << std::endl;
std::cout << "map2 contains: ";
for (std::map<int, char>::iterator i = map2.begin(); i != map2.end(); i++){
std::cout << i->first << " => " << i->second << ", ";
}
std::cout << std::endl;
return 0;
}