C++ Unordered_multimap Library - operator=() Function

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Description

The C++ function std::unordered_multimap::operator=() copy elements from initializer list to unordered_multimap.

Declaration

Following is the declaration for std::unordered_multimap::operator=() function form std::unordered_map() header.

C++11

unordered_multimap& operator=(intitializer_list<value_type> il);

Parameters

il − Initialize list.

Return value

Returns this pointer.

Time complexity

Linear i.e. O(n) in average case.

Quadratic i.e. O(n²) in worst case.

Example

The following example shows the usage of std::unordered_multimap::operator=() function.

#include <iostream>
#include <unordered_map>

using namespace std;

int main(void) {
   unordered_multimap<char, int> umm; 
   umm = {
            {'a', 1},
            {'b', 2},
            {'c', 3},
            {'d', 4},
            {'e', 5},
          };

   cout << "Unordered multimap contains following elements" << endl;

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

   return 0;
}

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

Unordered multimap contains following elements
e = 5
d = 4
c = 3
b = 2
a = 1