How does C++11 std::multimap handle duplicate keys?

Can you explain how C++11 std::multimap works with duplicate keys?

Sure! In C++11, std::multimap allows multiple elements to have the same key. This means you can store pairs of keys and values where the keys are not unique.

How do I insert elements into a multimap?

You can insert elements using the insert function. For example: multimap.insert(std::make_pair(key, value)); This will add the key-value pair to the multimap.

What happens if I insert a duplicate key?

If you insert a duplicate key, the new value will be added alongside the existing values for that key. You can retrieve all values for a key using the equal_range method.

Can you show me a code example?

Certainly! Here's a simple example:

#include <iostream>
#include <map>

int main() {
    std::multimap<int, std::string> mmap;
    mmap.insert({1, "apple"});
    mmap.insert({1, "banana"});
    mmap.insert({2, "cherry"});

    for (const auto& pair : mmap) {
        std::cout << pair.first << " : " << pair.second << std::endl;
    }
}

This will output both "apple" and "banana" for the key 1.