C++ Map Library - insert() Function

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Description

The C++ function std::multimap::insert() extends multimap by inserting new element from initializer list. This function increases container size by one.

Declaration

Following is the declaration for std::multimap::insert() function form std::map header.

C++11

void insert (initializer_list<value_type> il);

Parameters

il − Initializer list.

Return value

None

Exceptions

No effect on container if exception is thrown.

Time complexity

Logarithmic i.e. O(log n)

Example

The following example shows the usage of std::multimap::insert() function.

#include <iostream>
#include <map>

using namespace std;

int main(void) {
   /* Multimap with duplicates */
   multimap<char, int> m {
            {'a', 1},
            {'a', 2},
            {'b', 3},
         };

   m.insert({{'c', 4}, {'d', 5}});

   cout << "Multimap contains the following elements:" << endl;

   for (auto it = m.begin(); it != m.end(); ++it)
      cout << it->first << " = " << it->second << endl;

   return 0;
}

Let us compile and run the above program, this will produce the following result −

Multimap contains the following elements:
a = 1
a = 2
b = 3
c = 4
d = 5