Материал из C\C++ эксперт
Exchange the contents of two maps
#include <iostream>
#include <string>
#include <map>
using namespace std;
void show(const char *msg, map<string, int> mp);
int main() {
map<string, int> m, m2;
m.insert(pair<string, int>("A", 100));
m.insert(pair<string, int>("G", 300));
m.insert(pair<string, int>("B", 200));
// Exchange the contents of m and m2.
cout << "Exchange m and m2.\n";
m.swap(m2);
show("Contents of m: ", m);
show("Contents of m2: ", m2);
// Clear m.
m.clear();
if(m.empty()) cout << "m is now empty.";
return 0;
}
// Display the contents of a map<string, int> by using an iterator.
void show(const char *msg, map<string, int> mp) {
map<string, int>::iterator itr;
cout << msg << endl;
for(itr=mp.begin(); itr != mp.end(); ++itr)
cout << " " << itr->first << ", " << itr->second << endl;
cout << endl;
}
